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Basic Envisat SAR Toolbox

1. BEST User Manual v4 0 2 Check that the software is correctly installed by typing at the prompt the command best If the software is correctly installed you should see the following message BEST Generic Tool ver 3 0 beta best File ini not found The Tcl Tk HMI is launched by typing the command besthmi If you haven t already done so you will need to download Tcl Tk from the Tcl Developer Xchange http www scriptics com and install it according to the accompanying instructions 20 BEST User Manual v4 0 2 SunOS Solaris2 l 4a 4b It is first necessary to determine which shell will be used on the target system The default login shell for the SunOS is the Bourne shell but the C shell and the Korn shell are also possibilities At the prompt in a newly created shell type echo SSHELL The output indicates the current shell as follows bin sh gt the login shell is the Bourne shell bin csh the login shell is the C shell bin ksh the login shell is the Korn shell Create a home directory for BEST mkdir BEST Decompress the g zipped tar file after moving it to the directory previously created tar xvfz software tar gz This will extract the ready compiled BEST executables into the bin directory and the BEST shared library into the lib directory If the login shell is the C shell see 1 above modify the cshrc file found in the user s home di
2. GEOMETRIC CONVERSION Input Dir C BEST_out Output Dir C BEST_out Reference Image 109 XTs Input Coordinates Type ROW Input Coordinates 0 100 999 1999 100 250 Output Coordinates Type SATPOS Output File geoconv Output file geoconv txt 87 BEST User Manual v4 0 2 STB BEST ToolBox Telespazio ESA GEOMETRIC CONVERSION Reference Image dat i09 XTs ROW gt X SATELLITE POSITION Y SATELLITE POSITION Z SATELLITE POSITION 0 gt 5173858 256349 1665150 608019 4639795 873503 100 gt 5172906 319468 1665206 232858 4640834 441325 OUT OF IMAGE 999 gt 5183357 284946 1664590 037330 4629410 891974 1999 gt 5192846 092677 1664020 027111 4618997 901304 OUT OF IMAGE 100 gt 5174809 996228 1665094 894292 4638757 129063 250 gt 5176237 236584 1665011 157048 4637198 681331 To convert row column to latitude longitude In this case the tool is used to compute latitude longitude pairs from a list of row column pairs Note that for demonstration purposes two of the specified points lie outside the reference image under consideration GEOMETRIC CONVERSION Reference Image i09 XTs Input Coordinates Type ROWCOL Input Coordinates 0 0 100 0 999 999 1999 0 100 250 150 250 O
3. It is much faster to use the PORTION EXTRACTION tool to generate sub scenes from data that is already in the BEST internal format compared to extracting data directly from a tape or CD using the FULL RESOLUTION EXTRACTION function It may therefore be of benefit if the location of a feature is uncertain to first use FULL RESOLUTION EXTRACTION to ingest a region of interest that is larger than necessary and subsequently identify and extract a smaller sub scene using PORTION EXTRACTION In this way it will only be necessary to use the relatively slow FULL RESOLUTION EXTRACTION function once The input image must be in the BEST internal file format and can be any size it does not need to correspond to an entire full resolution data set The area of interest AOD to be extracted can be specified in all of the methods described in Appendix 4 excluding the example image mode but including the polygonal AOI In the latter case pixel values outside the AOI are set to zero When the input image does not contain the orbital and timing annotations as in the case of images obtained with the IMPORT RASTER IMAGE function the specification of the AOI using latitude and longitude is not possible Typical Processing Chain HEADER ANALYSIS gt FULL RESOLUTION EXTRACTION gt PORTION EXTRACTION Example INI file PORTION EXTRACTION Input Dir C BEST_out Output Dir C BEST_out Input Image fullres_data xXTs Top Left Corner 0 0 Bottom
4. HAN 36 BEST User Manual v4 0 2 Typical Processing Chain HEADER ANALYSIS gt QUICK LOOK Example INI file QUICK LOOK Input Media Path C Data ASAR ASA_WSM_1P 0053 N1 Input Media Type disk Input Dir C Data ASAR Output Dir C Data ASAR Header Analysis File header_WSM HAN Output Quick Look Image ql_WSM Output Grid Image qlg_WSM Quick Look Presentation GEOGRAPHIC Number of Grid Lines 8 8 Output Image Size 800 0 Window Sizes 3 3 Grid Type LATLON Grid Drawing Mode transparent Rough Range Calibration APPLY Dismount Volume N Parameter Summary Quick Look Generation Input Media Type The source media of the product tape Exabyte cdrom disk product on hard disk file BEST internal format Example Input Media Type cdrom mandatory parameter Input Media Path The path of the media unit or when Input Media Type is set to file the file name of the input internal format image fora PC CDROM use Input Media Path D data ASAR DS1 ASA_IMP_1P 320 N1 for a Unix EXABYTE device use Input Media Path dev rst1 fora Unix CDROM device use the entire path to the selected scene ERS SAR product CDROMs can have multiple scenes on them Input Media Path cdcom SCENE1 mandatory INPUT BEST extension not applicable IF Input Media Type is
5. cdrom Header Analysis File header_IMP HAN Output Image full_res_IMP Coordinate System LATLON Centre 52 406 4 470 Size Unit KM Size 3 1 6 3 D data ASAR DS1 ASA_IMP_1P 320 N1 10 BEST User Manual v4 0 2 Supposing the file is called full_res ini the tool would be run using the command BEST full_res ini It is useful to examine the contents of the file full_res ini to understand the meaning of the various instructions Many further details about the options available for the FULL RESOLUTION EXTRACTION tool can be found in the main section of the User Manual FULL RESOLUTION This is the name of the function C BEST_out Input Dir The path to the directory containing the required input files in this case the header file header_IMP HAN Output Dir C BEST_out The path to a directory where the output files will be wrtitten Input Media Path D data ASAR This path directs the tool to the device and the product to be analysed In this case it is a CD drive mounted on the D drive Input Media Type cdrom The medium on which the data is held Header Analysis File header_IMP HAN The required input file for this function which contains information about the data product and was created by the HEADER ANALYSIS function Output Image full_res_IMP The name of the output file
6. the type float or complex depends on the input image type The following table for shows the type of the output image when one of the SUM SUB MUL and DIV operators is applied to two input images i r 22s 2 If c Ti aE or oe oe m Do er Ic Note that in case of operations between a real image i s and f and a complex one r t and c the real image is considered as a complex image having the imaginary part set to 0 The type of the output image resulting from one of SUM SUB MUL and DIV operators applied to one input image and a constant which is of float type depends on the type of the input image as shown in the following table i r s IN f 22 In case of operations between one complex image r t and c with a constant the constant value is considered as a complex number having the imaginary part set to 0 The output image type of ABS operation is always of float type OPP 84 BEST User Manual v4 0 2 Selecting an Area of Interest An area of interest can be selected with the usual SAR Toolbox rules Coordinate System Top Left Corner Bottom Right Corner etc parameters except for polygonal AOI Number of Vertex Vertex couples which are not allowed see Appendix 4 for further details about AOI specification When executing the absolute value of one image or when adding subtracting multiplying or dividing
7. 20 273291 17 951748 OUT OF IMAGE 999 999 gt 21 202480 18 768332 1999 0 gt 20 283932 17 961334 OUT OF IMAGE 100 250 gt 20 506369 18 156677 150 250 gt 20 506618 18 156904 To convert latitude longitude to row column Finally the tool is used to compute the row column location of selected latitude longitude geographic coordinate pairs Note that for demonstration purposes one of the specified locations lies outside the reference image under consideration GEOMETRIC CONVERSION Reference Image 109 XTs Input Coordinates Type LATLON Input Coordinates 41 188416 14 906085 41 102253 14 728530 41 183374 14 8 41 0 16 0 Output Coordinates Type ROWCOL Output File geoconv Output file geoconv txt STB BEST ToolBox Telespazio ESA GEOMETRIC CONVERSION Reference Image dat 109 XTs LATITUDE LONGITUDE gt ROW COLUMN 41 188416 14 906085 gt 0 0 41 102253 14 728530 gt 999 999 41 183374 14 866438 gt 100 250 41 177875 14 864826 gt 150 250 41 000000 16 000000 gt 31 7540 OUT OF IMAGE Parameter Summary Geometric Conversion Reference Image The name of the integer image in internal format for which conversions will be computed Example Referenc mandatory INPUT BEST extension 1 277 270
8. 228 220 r where indicates that any BEST module could have produced this file Image tl_priimage XTs Input Coordinates Type The type of input coordinates to be transformed ROWCOL row column pairs LATLON latitude longitude coordinates ROW list of image rows Example mandatory parameter ROW COL Input Coordinates Type 89 BEST User Manual v4 0 2 Input Coordinates A list of comma separated row column or latitude longitude pairs or a list of comma separated image row numbers depending on the Input Coordinates Type parameter to be converted Example Input Coordinates 0 0 999 999 100 250 150 250 mandatory parameter Output Coordinates Type The type of output to be computed LATLON row column pairs ROWCOL latitude longitude coordinates INCLOK incidence angle and look angle SATPOS satellite position X Y Z triplets Example Output Coordinates Type LATLON mandatory parameter Output File The name of the output file containing the computed conversions an extension tx is automatically added by the system Example output Image float_img mandatory OUTPUT BEST extension txt 90 BEST User Manual v4 0 2 Slant Range to Ground Range Conversion Description The SLANT TO GROUND RANGE CONVERSION tool reprojects data complex as SLC products in internal form
9. 3 Example Transformation Degree 1 5 optional parameter default is 1 5 Interp Window Sizes The size in pixels of the processing image blocks into which the master image is subdivided This affects the accuracy only when the Interpolation Mode is set to CONSTANT SHIFT in one or both directions however it always affects the running time it is faster to use large blocks Example Interp Window Sizes 150 150 optional parameter default is 512 512 Interpolation Mode The interpolation method NEAREST NEIGHBOUR BILINEAR CONSTANT SHIFT CUBIC CONVOLUTION SINC CONSTANT SHIFT CUBIC CONV CONSTANT SHIFT SINC Note that the cubic convolution does not work very well with complex data It is strongly recommended that a constant shift or sinc interpolator is used for complex data Example Interpolation Mode CUBIC CONVOLUTION optional parameter default is SINC Interpolation Inverse Precision The length of lookup tables used to speed up the sinc interpolation High values give a good accuracy at the expense of an increased memory requirement The accuracy that can be achieved is given by the reciprocal of this parameter 1 e the default value 1000 gives an accuracy of 1 1000 of a pixel Example Interpolation Inverse Preci sion 1000 optional parameter default is 1000 Sinc Width 122 BEST User Manual v4 0 2 T
10. Input Image input APf Top Left Corner 50 50 Bottom Right Corner 500 500 Window Sizes 11 11 PFA 10 0 Scatter Threshold 0 57 Mask File user_mask ker Number of Look 3 0 Edge Threshold 0 82 Line Threshold 0 87 Output Image specklefiltered_img 137 BEST User Manual v4 0 2 Speckle Filter Summary Table Parameter Description Comment Example the name of the real input image in internal mandatory INPUT format containing intensity i e power BEST extension APf data this image can come from a PRI or a SLC data but in the latter case a modulus extraction shall be performed before the power conversion Example Input Image tl_priimage APf AOI specification only the Rectangular AOI specifications _joptional parameter if not are permitted see Appendix 4 present the entire input images are assumed indow Sizes the size of the speckle filter in pixel units mandatory parameter row col ordering For example indow Sizes 11 11 the Probability of False Alarm in the vari mandatory parameter lous regions recognition expressed in per centage units the lower is this value less filtered is the output image due to the fact that we are recognizing the various regions under a very strict criterion Scatter Threshold the threshold used for the scatter detection mandatory parameter higher is this value less preserved are the scatters in the output image due to the fact that we ar
11. band1 XTs band2 XTs band3 XTs band4 XTs bil_img 67 BEST User Manual v4 0 2 Parameter Summary Export to BIL Input Images The input image list Example Input Images band1 XTs band2 XTs band 3 XTs band4 XTs mandatory INPUT BEST extension 1 f c 22s or t where indicates that it is not important which module created the files as long as the data type is correct Output Image The name of the BIL output image containing multi band data an extension BG is added by the system and the associated ASCII header file an extension ers is added by the system Example Output Image tiff_img mandatory OUTPUT BEST extension BG and ers Output Annotations File The name of the output file containing the annotations data of the first listed input image an extension tx is added by the system Example output Annotations File output_annot mandatory OUTPUT BEST extension txt 68 BEST User Manual v4 0 2 Export to RGB Description The EXPORT TO RGB tool converts three internal Toolbox format images with the same size into a 24 bit RGB image which can be read by other image handling software packages Only images with a single sample per pixel can be given as input No AOL is permitted with this tool Example INI file RGB GENERATION Input Dir C BEST rgb Output D
12. ile creation time for aux file s a amy Bee ee ee pe a a 8 ee a seconds envisat_duration Seas ONS So a C a1 ID be ng S envisat_phase_id X if not used 12 Cycle Number within the phase 034 Be envisat_cycleno a Bere ee as amy en a anak en Er Na ee N ex 14 Orbit Number relative to the start of pr 00065 orbit num a eee oduct as amy WE L a Siete ee eee ne 16 Absolute Orbit Number iui O e envisat_absolute_orbitno a7 awy A A A ne te A ren 18 Product Type File Counter 0972 REN TE envisat_prod_ty_file_coun 0000 to 9999 then wraps to 00 ter 00 Be Pr O E e So ee Se ee ze 20 satellite 1D Mo aes envisat_sat_id ENVISAT 1 N1 ERSI E1 ERS2 E2 Sean amy ER Sand Nn 22 Processing stage Flag PROC_STAGE N ER EN Se we a EIER 23 Reference Document Describing Product REP_DOC PO RS MDA GS2009 ae E _08_3H a ME ee a en 25 Acquisition station COLE BIR Te ANA NS F 26 Processing Center Tag PROC_CENTER Ev ER ea a a ee re 27 Processing Center ID URPAG processing paf Processing Center which genera ted this product 159 BEST User Manual v4 0 2 if not used it s all spaces 34 UTC Start Time of data sensing SENS ING_STAR 22 JAN 200 UTC 2 for Level0 products use this v 5 09 55 56 061990 alue for Levell use the one i n the SPH 35 UTC Stop Time of data sensing 22 JAN 2005 UTC for Level0 products use this v 09 56 13 061654 alue for Levell use the one i n the SPH 71 UTC time correspon
13. 2 Coherence Generation Calculates the phase coherence between two co registered complex images 3 Footprint Registration Indicates on a quick look of a master image the footprints of up to 10 co registered slaves 4 Image Geo correction Reprojects ASAR medium resolution imagery to a UTM or UPS planar grid 5 Amplitude Coherence Multi layer Composite Generates a multi layer pseudo true colour composite image consisting of the coherence between two co registered images with either their mean backscatter and the backscatter difference or the detected images of the master and slave 6 Doris Baseline Evaluation Calculates the baseline based on input DORIS orbit files between the nearest point of two orbits to a specified ground location 113 BEST User Manual v4 0 2 Co registration General The CO REGISTRATION tool will co register one slave image or a set of slave images with respect to a master image The function is fully automatic in the sense that it does not require the user to manually select tie points from the master and slave images The co registration is performed in 1 2 or 3 steps 1 An initial registration step is performed using the satellite orbit parameters 2 By default a coarse registration is achieved using a cross correlation operation on a series of cells defined across the images This step may be disabled by changing the flag parameter Image Coarse Reg 3 By defau
14. BEST User Manual v4 0 2 C APPENDICES BEST User Manual v4 0 2 Appendix 1 Example of a Header Analysis output file An example of the ASCH Header Analysis output file is shown here However these files are very long so only a subsection is shown here to provide an example of its format The following information is given in the six columns e parameter sequential number e name of the field as it appears in the ESA format documentation e value of the parameter e units in which the parameter is expressed e internal field name as it appears in the parameter dump obtained with the data conversion tool e aremark Processing time Product type Sensor Mode Image Source ASAR Data format MPH SPH Facility id Format descriptor reco File name DF PRODUCT_DATA_FILE Record name Main Product Header Record Pos Esa field name Value Units Tag Remark 1 dummy PRODUCT be F 2 Product Tag ASA_IMS_1PNUPA20050122_09 product_name contains the string PRODUCT 5556_000000162034_00065_1 5149_0972 N1 3 Product ID ASA_IMS_1P envisat_prod_id Processing State Flag oe envisat_proc_state_flag should be equal to the one bel ow C 5 originator 10 wa DECE TAT gavigatuorigingtos o aS estat pay 20050122 gnyigatstartday 7 Start day of first MDSR or fi le creation date for aux files 7 dummy gstart Time er envisat_start_time Start time of first MDSR or
15. This lookup table should be in the form of an ASCII file contain pairs of numbers which define the way in which the values of the input image are mapped onto the 256 intensity values that are available for the 8 bit output image 71 BEST User Manual v4 0 2 The following examples illustrate the format that is used in the look up tables Look Up Table Format for Gain Conversion Example 1 Yu 060 100 200 300 500 800 1000 2000 In the figure above the x axis represents the input values and the y axis represents the output values The mapping between this input and output is described by the following look up table 0 50 10 100 20 200 30 300 50 500 80 800 120 1000 200 2000 The first pair of numbers are O and 50 this indicates that all pixels in the input image with a value 50 or less are mapped to 0 in the output image The second pair of numbers are 10 and 100 showing that all pixels in the input image that are between 51 and 100 are mapped to 10 in the output image The third pair is 20 and 200 indicating that the input pixels with values in the range 101 to 200 are mapped to 20 in the output image As can be seen from this example it is not necessary for there to be a separate pair of entries for all of the possible 256 output values Also it should be noted that it is not required that the first output value refers to 0 and the last to 255 If the entry corresponding to the output value 255 is missing as in the ex
16. Y N An extensive use of the symbol inside the INI files allows to build more general files both reusable and closer to program instructions The following two INI files can be used for applying the gain conversion module to an input image and then passing the converted image tmp GCi to TIFF format At the end the converted image is deleted GAIN CONVERSION Input Image Output Image tmp Min Percentage Max Percentage Number of Black Levels 0 0 TIFF GENERATION Delete Input Image Y Input Images tmp GCi Output Image The following text shows the related output obtained from its execution bold style refers to user supplied parameter values and GC2TIFF INI is a text file containing both of the above GAIN CONVERSION and TIFF GENERATION INI file instructions stbx GC2TIFF INI SAR TOOLBOX Generic Tool ver 1 2 Doing GAIN CONVERSION Enter a STRING value for Input Image i09 XTs Enter a NUMBER value for Min Percentage 1 0 Enter a NUMBER value for Max Percentage 99 0 186 stbx warning No AOI parameters found Get the whole image 95 completed GAIN CONVERSION completed Doing TIFF GENERATION Enter a STRING value for Output Image 109 95 completed TIFF GENERATION completed BEST User Manual v4 0 2 187 BEST User Manual v4 0 2 Exploiting the UNIX and DOS operating system pipe capability Exploiting the UNIX and DOS opera
17. esp Number Of Volumes 1 Annotation File header_IMP Header Analysis File header_IMP Dismount Volume N Supposing the file is called header_analysis ini the tool would be run using the command BEST header_analysis ini It is useful to examine the contents of the file header_analysis ini to understand the meaning of the various instructions Many further details about the options available for the HEADER ANALYSIS tool can be found in the main section of the User Manual HEADER ANALYSIS This is the name of the function This indicates path to a directory where the output files will be written Output Dir C BEST_out This path directs the tool to the device and the product to Input Media Path D data ASAR be analysed In this case it is a CD drive mounted on the D drive The medium on which the data is held In this case a CD Input Media Type cdrom ROM from an ESA PAF Sensor Id ASAR The instrument or platform that acquired the data cog Pr For ASAR images the mode in which the data was Sensor Mode Image es acquired In this case it is Image Mode Product Type PRI The level to which the data is processed by the PAF BEST User Manual v4 0 2 Data Format ENVISAT The data format The PAF at which the data was processed This is Source Id esp relevant for ERS data
18. for DPAF products UKP for UKPAF products ITP for IPAF products SIS for SINGAPORE products or in general a three character string all the three character are used to identify the source processing facility Within a VOLUME SECTION i the structure is VOLUME i FILE SECTION FILE SECTION 2 FILE SECTION M where iis a integer number which increases with each volume 56 BEST User Manual v4 0 2 Within a FILE SECTION j the structure is FILE j RECORD SECTION RECORD SECTION 2 comparation_flag RECORD SECTION S where j is a integer number which increases with each file comparation_flag which can be Y or N tell to the system to use or not this information during the comparation of the media structure obtained scanning the media with the values in the nominal media structure file Each RECORD SECTION k has the following aspect RECORD where recs_number rec_lencomparation_flag recs_number is the number of sequential records of the same size rec_len is the record length in bytes common to all the rec_len records comparation_flag which can be Y or N tell to the system to use or not this information during the comparation of the media structure obtained scanning the media with the values in the nominal media structure file An example of one entry of the nominal media structure file is PRI SENSOR ERS1 FORMAT CEOS SOURCE ITP VOLUME 1 FILE 1 Y RECORD 4 360Y FILE 2 Y RECORD 1 720
19. high residual errors Example Editing RMS 1 0 optional parameter default is 1 0 Coarse Reg Window Sizes The size of the cells used for the coarse registration step expressed in row col Each cell is centred on one of the GCP positions and the cross correlation is performed within it Example Coarse Reg Window Sizes 51 51 optional parameter default is 51 51 Coarse Reg Interp Factors The interpolation factors for the coarse registration step The values are expressed as row col in units of pixel This parameter defines the step size used in the cell cross correlation process Higher values produce good accuracy at the expense of longer running times Example Coarse Reg Interp Factors 3 5 3 5 optional parameter default is 1 0 1 0 Coarse Reg Tolerance The coarse registration step is performed twice using slightly different cell positions If the final GCP positions from these two steps do not agree to within the limit set by this parameter then these GCPs are not used in the remainder of the co registration process Example Coarse Reg Tolerance 1 0 optional parameter default is 1 1 Image Fine Reg Determines whether the 3 fine registration step should be performed on the data For complex data this will entail the maximisation of the complex coherence For real data it will entail the refinement of the cross correlation function Example Image Fine Reg N optional parameter defa
20. which will be in the Toolbox internal format and which will be given the extension XTs if the input image is PRI data as in this case or XTt ifthe input image is SLC data The coordinate system used to define a subset of the data set for extraction In this case the location of the region of interest is identified by latitude and C di te Syst LATLON ee longitude the coordinates might be derived from the superimposed grid on the quick look image generated previously The location of the region of interest defined in this Centre 52 406 4 470 case by the coordinates at its centre given in decimal degrees Size Unit KM The system of units used to define the size of the region of interest to be extracted In this case kilometres Size 3 1 6 3 The size of the region of interest given in km The output from the Full Resolution Extraction function i e full_res_IMP XTs may be viewed either as a quick look image or by exporting to TIFF after first applying the GAIN CONVERSION tool to adjust the dynamic range of the pixel values and convert the data to 8 bits BEST User Manual v4 0 2 3 BEST Functions Summary This chapter contains a brief summary of all the BEST functions Data Import and Quick Look tools 1 Header Analysis Decodes the product header and stores the information in an internal Toolbox format file necessary for input to the FULL RESOL
21. 0 input_lines_nb 0 spread_loss_comp_flag 0 nb_data_points 5 log_vol_id ENVI ASA SLC gr_sr_pol_degree 0 near_zero_fill_pixel_number 0 far_zero_fill_pixel_number 0 orbit_direction DESCENDING prf 1652 415649 cross_dopp_freq_quartic 0 000000 envisat_first_vect_mjd_days 1848 envisat_2nd_vect_mjd_days 1848 envisat_first_vect_mjd_seconds 35756 envisat_first_vect_mjd_microsec 517081 envisat_2nd_vect_mjd_seconds 35760 envisat_2nd_vect_mjd_microsec 585519 envisat_3rd_vect_mjd_days 1848 envisat_3rd_vect_mjd_seconds 35764 envisat_3rd_vect_mjd_microsec 653956 envisat_4th_vect_mjd_days 1848 envisat_4th_vect_mjd_seconds 35768 envisat_4th_vect_mjd_microsec 722394 envisat_5th_vect_mjd_days 1848 envisat_5th_vect_mjd_seconds 35772 envisat_5th_vect_mjd_microsec 790831 envisat_source_file ASA_IMS_1PNUPA20050122_095556_000000162034 00065 ls_en_conv_coeff_1 0 000000e 000 ls_en_conv_coeff_2 0 000000e 000 ls_en_conv_coeff_3 0 000000e 000 ls_en_conv_coeff_4 0 000000e 000 ls_en_conv_coeff_5 0 000000e 000 ls_en_conv_coeff_6 0 000000e 000 ls_en_conv_coeff_7 0 000000e 000 ls_en_conv_coeff_8 0 000000e 000 en_ls_conv_coeff_1l 0 000000e 000 en_ls_conv_coeff_2 0 000000e 000 en_ls_conv_coeff_3 0 000000e 000 en_ls_conv_coeff_4 0 000000e 000 en_ls_conv_coeff_5 0 000000e 000 en_ls_conv_coeff_6 0 000000e 000 en_ls_conv_coeff_7 0 000000e 000 en_ls_conv_coeff_8 0 000000e 000 actual_pr
22. 0 2 Image Geo correction Description The GEO CORRECTION tool performs a geocoding process to georeference input ASAR Medium Resolution i e ASA_IMM_1 ASA_WSM_1 or ASA_APM_1 real images It uses the Geolocation Annotation in the product header to reproject the data to a flat earth ellipsoid no kind of terrain relief is considered for such operation The output image is hence distorted so that its vertical and horizontal axes are aligned to the North and East axes of the selected cartographic projection UTM or UPS The Geocorrection is based on the following steps e creation of a regular grid in the selected cartographic reference system having a spacing between the nodes equal to the input pixel and line spacing e transformation of the grid nodes from cartographic into input image coordinates row col e interpolation of the input image to generate the output image using the previously generated grid The new annotated information new corner localisation the correspondence between lat lon and row col etc is computed and updated in the output file The method of interpolation is selected using the Interpolation Mode parameter The fastest and least accurate method is the bilinear interpolator the most accurate is cubic convolution The sinc interpolator is most precise The following interpolators may be used e Bilinear uses three linear interpolations of the four pixel values around the position determi
23. 1 7 Finally this INI file makes it possible to obtain the absolute value of one image IMAGE OPERATION Input Images imagein Operation Type ABS Output Image imageout The parameter Input Images is mandatory and is used to specify one at least or two and no more input images The allowed values for the mandatory parameter Operation Type are SUM to sum two images or to sum one image with a constant SUB to subtract the second defined image from the first defined image or to subtract a constant from one image MUL to multiply two images or to multiply one image with a constant DIV to divide the first defined image by the second defined image or one image by a constant ABS to have the absolute value of one image The Output Image parameter is mandatory and is used to specify the output image The Constant Factor allows to specify the value for summing subtracting multiplying or dividing one image with a constant The allowed types for input images are 8 bits Unsigned Integer i for 8 bit TIFF images Complex 8 bits Unsigned Integer r for RAW products 16 bits Unsigned Integer s for PRI GEC GTC products 83 BEST User Manual v4 0 2 Complex 16 bits Signed Integer t for SLC products 32 bits Float f for internal format files Complex 32 bits Float c for internal format files The output image has the extension OP
24. ADf 149 BEST User Manual v4 0 2 Gamma Image Generation ERS Description The GAMMA IMAGE GENERATION tool converts a backscatter image i e output from the BACKSCATTERING IMAGE GENERATION tool into a Gamma image This is achieved by dividing the backscatter image by the cosine of the satellite incidence angle For certain terrain types the application of this function will make the backscatter image independent of the satellite incidence angle The area of interest AOI of the input image can be specified in any way except the example image mode and the output image may have either a linear or dB scale Example INI file IMAGE GAMMA Input Dir C BEST_out Output Dir C BEST_out Input Image sigma_0 BSf Output Image Scale DB Output Image gamma Parameter Summary Gamma Image Generation Input Image The name of the input image in internal format containing backscatter data Example Input Image sigma_0 AP f mandatory INPUT BEST extension BSf AOI specification See Appendix 4 the example image mode is not permitted optional parameter default is entire input image Output Image Scale The scale of the output backscatter image LINEAR _ DB Do not use the dB scale if a further step of averaging is foreseen Example Output Image Scale DB optional parameter default is LINEAR Output Image The name of the output image in internal for
25. APPLY Reference Replica Power 205229 0 156000 0 ADC Saturation Correction APPLY ADC Saturation Correction File pri_adc ADf Calibration Constant Correction APPLY Output Image Scale DB Output Image pri_s0 The following ini file is an example of fully compensated backscattering image generation from a SLC power image processed at a PAF that annotates the chirp density value in the SLC the antenna pattern and the range spreading loss are not corrected during the SAR processing and shall be compensated here IMAGE BACKSCATTERING Input Dir C BEST_out Output Dir C BEST_out Input Image slc APf Antenna Pattern Correction APPLY Range Spreading Loss Correction APPLY Replica Power Correction APPLY Reference Chirp Average Density 267200 201060 ADC Saturation Correction APPLY ADC Saturation Correction File slc_adc ADf Calibration Constant Correction APPLY Output Image Scale DB Output Image slc_s0 Typical Processing Chain In the case when ADC saturation correction is required the sequence of processing steps could be the following PORTION EXTRACTION gt AMPLITUDE TO POWER ADC COMPENSATION GENERATION gt IMAGE BACKSCATTERING Parameter Summary Backscattering Image Generation ERS Input Image The name of the input image in internal format containing intensity power data from which the backscattering image will be generated E
26. Both the Top Left Bottom Right Corners couple and the Top Right Bottom Left Corners can be specified in one of the two coordinate systems geodetic latitude longitude row column The Center point can be specified in one of the two coordinate systems geodetic latitude longitude row column The Size can be specified in kilometers unit pixel units The polygonal AOI can be specified through the following data the number of the vertices of the polygon the coordinates of the vertices The vertices can be expressed in the following coordinate systems geodetic latitude longitude row column Note that the polygon area is built following the specified order of the vertices The following table summarizes the various specifications of the AOI with the related portions of the INT file AOI Specification Rectangular Coordinate System ROWCOL the first coordinate is for row Top Left Bottom Right Top Left Corner 100 200 the second for column Bottom Right Corner 300 500 the row col coordinate system is assumed by default if the 174 Top Left Bottom Right corners Lat Lon coordinates Rectangular Top Right Bottom Left cor ners Row Column coordinates Rectangular Top Right Bottom Left corners Lat Lon coordinates Rectangular Center in row col Center in lat lon Size in km Vertices in row col Polygonal Vertices in lat lon Coordinate System LATLON Top Left Corner 52 70 6 30 Bottom Right Corn
27. Float Conversion IFf Ancillary Data Dump txt Image Operation OP Geometric Conversion txt Slant to Ground Range Conversion SG SGc Flip Image FI Sensitivity Vector Evaluation txt N B is replaced with the equivalent format indicator of the input data BEST User Manual v4 0 2 BEST Internal Format The internal format adopted in BEST is called TTIFF or Tiled Tagged Image File Format TTIFF is a particular form of the commonly used TIFF format The differences are essentially associated with the name of some image parameters which in the TIFF terminology are called tags and with some restrictions in the image organization An extended discussion of this topic is given in Appendix 7 The internal format TTIFF files can be read by standard display software packages like XV for UNIX or ULEAD for PC if the viewer supports the data type contained in the file For example it is possible to read 8 bit integer internal format images using XV 8 bit integer images have the Toolbox file extension 7 where the question marks represent upper case letters indicating the module used to produce the image Of course the EXPORT TO TIFF and EXPORT GEOTIFF tools allow any 8 bit Toolbox image to be converted to the standard TIFF format Internal format data that is not 8 bit can be converted to 8 bit using the GAIN CONVERSION tool Important When viewing a TIFF image generated by BEST or an internal format f
28. GCi green GCi blue GCi Delete Input Image N Output Image rgb_img Output Annotations File anno_rgb Parameter Summary Export to TIFF Input Images The name of internal format image s to be converted Where three images are listed for an RGB TIFF they should be in the order red channel green channel blue channel Example Input Image asar_apm XTs mandatory INPUT 65 BEST User Manual v4 0 2 BEST extension 7 2 s 220 2 f or 2c where indicates that any BEST module could have produced these files Output Image The name of the output standard TIFF image the extension tif is automatically added by the system Example Output Image apm_tif mandatory OUTPUT BEST extension tif Output Annotations File The name of the output ASCII file containing the annotation data the extension txt is automatically added by the system Example Output Annotations File anno_tif mandatory OUTPUT BEST extension txt 66 Export to BIL Description BEST User Manual v4 0 2 The EXPORT TO BIL tool converts one or more up to ten real or complex images into a binary file arranged in the band interleaved by line BIL format A maximum of 10 images in the BEST internal format can be submitted as inputs as long as they all share the same data type integer or floating point and size The output can be read by many image
29. IMM APM WSM SLC Complex products IMS APS GEC Geocoded products IMG APG BRW Browse products IM__BP AP__BP WS__BP GM__ BP RAW ERS SAR RAW products Example Product Type pri mandatory parameter Data Format The format of the product ceos for ERS data Envisat for Envisat data in mphsph format Example Data Format envisat mandatory parameter 31 BEST User Manual v4 0 2 Source Id The PAF or station where the data was processed esp for all Envisat data and ERS data processed at ESRIN products dep for ERS data processed at D PAF ukp for ERS data processed at UK PAF itp for ERS data processed at I PAF sis for ERS data processed at Singapore Station fst for ERS data processed by an ACS w k processor in Argentina Cordoba China Beijing Ecuador Cotopaxi Israel Tel Aviv Kenya Malindi Russia South Africa or Thailand Bangkok Example Source Id esp mandatory parameter Number Of Volumes The number of Exabyte cassettes into which the entire product is subdivided usually 1 Example Number Of Volumes 1 mandatory parameter IF Input Media Type is tape Annotation File The name to be given to a text file that will contain a listing of all the header parameters an extension tx is automatically added by the system Example Annotation File header_IMP mandatory
30. Import Raster Image Converts an image in raster format into the Toolbox internal format without having to specify the number of file header bytes or line header bytes Also generates an ASCII file containing the image size information which is compatible with the ERMAPPER ers format BEST User Manual v4 0 2 Data Export tools 1 Export GeoTIFF Converts data from internal format to a GeoTIFF image that includes geographic information 2 Export to TIFF Converts 8 bit data from the Toolbox internal format to standard TIFF format as either single channel greyscale or 3 channel colour images 3 Export to BIL Converts one or more up to ten internal Toolbox format images having the same size and data type to one binary image in BIL Band Interleaved by Line format 4 Export to RGB Converts three internal Toolbox format images with the same size to a 24 bit RGB image Data Conversion tools 1 Gain Conversion Rescales floating point or real 16 bit integer data to 8 bits thereby preparing it for export to formats that can be visualised in basic graphics packages 2 Power to Amplitude Conversion Converts a power image into an amplitude image 3 Amplitude to Power Conversion Converts an amplitude image into a power image 4 Linear to dB Conversion Converts an amplitude or intensity image with a linear scale into an image in decibel dB units 5 Complex to Amplitude Conversion Derives the amplitude modulus from a
31. Right Corner 511 511 Output Image fullres_portion Parameter Summary Portion Extraction Input Image The name of the input image in internal format Example Input Image fullres_data xTs mandatory INPUT BEST extension 77 P 22c 729s 220 2 r where indicates that it is not important which BEST module produced the file AOI specification See Appendix 4 the example image mode is not permitted and the latitude longitude mode is permitted only if the orbital and timing information are present optional parameter default is entire input image Output Image 43 BEST User Manual v4 0 2 The name of the image containing the image portion an extension XT is automatically added by the system where indicates that the output image retains the same format as the input image Example Output Image fullres_portion mandatory OUTPUT BEST extension XT where indicates that the output image retains the same format as the input image 44 BEST User Manual v4 0 2 Image Preview Description The IMAGE PREVIEW function extracts a region of interest from a quick look image i e a tif image generated using the QUICK LOOK GENERATION function This function is useful to verify that the definition of an AOI is correct before extracting the region from a full resolution image The output image is in the same standard TIFF forma
32. bottom left corner of the scene for ascending passes and the top right corner for descending passes By applying a vertical or horizontal flip the image can be oriented so that north is up south is down west is left and east is right The flip is based on the row col reference system and can be executed with respect to the vertical axis the horizontal axis or to both at the same time HMI lolx Input Dir Sc ASAR_Toolbox Input Image full IMS XTs Output Dir Sc Output Image flip_IMP FI Flip Mode Horizontal C Vertical G Both Parameters record file name ini file ADI spec 4 Typical HMI settings fip_IMFI ini Ok Quit ER for an ASA_IMP_IP product Typical Processing Chain HEADER ANALYSIS FULL RESOLUTION FLIP IMAGE 94 BEST User Manual v4 0 2 Example INI file FLIP IMAGE Input Dir C BEST_out Output Dir C BEST_out Input Image asar_img XTs Delete Input Image N Output Image vflp_img Flip Mode vertical Parameter Summary Flip Image Input Image The internal format image to flipped Example Input Image asar_img XTs mandatory INPUT BEST extension 71 22s 220 2 P or c where indicates that any BEST module could have produced these files AOI specification see Appendix 4 for polygonal AOI the surrounding rectangular AOI is used optional parameter default is enti
33. by the rectangular method with corners expressed in row col Example INI file PRINCIPAL COMPONENT ANALYSIS Input Dir Output Dir Input Images imgl XTf img2 XT PCA Output Images pc1 pc2 Parameter Summary Principal Component Analysis Input Images The names of two input real images in internal format in acomma separated list Example Input Images imgl XTf img2 XT mandatory INPUT BEST extension s 217 f where indicates it is not important which module created the files as long as the data type is correct AOI specification see Appendix 4 only the rectangular method with corners expressed in row col may be used optional parameter default is entire input image PCA Output Images The names of the output images in internal format containing the first and second Principal Components the extension PCf is automatically added by the system in a comma separated list Example PCA Output Images pc1 pc2 mandatory OUTPUT BEST extension PCf 104 11 Resampling BEST User Manual v4 0 2 This chapter documents the following tools 1 Oversampling Up Sampling Resamples an image to increase the number of pixels 2 Undersampling Down Sampling Resamples an image to reduce the number of pixels 105 BEST User Manual v4 0 2 Oversampling Up Sampling Description The Oversampling function up samples a rea
34. bytes of the image records Pe N csc cee of the variable which contain the start line of the image contained in the actual volume END_LINE initialization of the variable which contain the end line 59 BEST User Manual v4 0 2 ee f the image contained in the actual volume Structure Section It describes the main structure of the product to which the description file is referred Since a product generally consists of more than one file this section describes File Number indicates the file ordinal number within the product Product File Name a self explanation string about the file Product File Code the extension used for the file onto the disk Presence Type Code and Can Be Interrupt flag these two fields encode how products can span over more than one medium when necessary because of the product dimensions compared with medium capacity File Format Code the physical format fixed length variable length etc File Record Length optional the default record size for each file File Sections Each file section one section for each file of the actual product describes the structure of the file it refers to Since a file can be considered as a sequence of records a file section consists of a sequence of record sections each of one describes the logical format of the referred record Record Sections Since a record can be considered as a sequence of fields each record section is a sequence of field sections each of one d
35. compatibility is maintained and it is possible to import and export images in TIFF with the same routines as the BTIFF one The BTIFF has no limits in the handling of the multi band data and or having a pixel size different from 8 bit e g complex images and so on It is possible to compress the image via the LZW algorithm The parameters can be maintained in their natural format e g the strings are kept as strings and the numbers as their binary representation and NOT as strings too Efficiency in read write operations with respect to the memory buffer usage is granted by tuning two parameters which controls the row and column dimensions of the tile i e the elementary unit of the image At IPAF we use a tile of 100 pixels 100 lines but different values can be used and this is both transparent to the user and maintains the compatibility New TIFF specifications TTIFF were issued in parallel to the development of the BTIFF format These are largely compatible but differ at a few points the name of some parameters are different e g BLOCKOFFSET has the tag 324 in the TTIFF and 273 in the BTIFF the number of rows and columns of the tile are constrained to be a multiple of 16 for TTIFF no limitations for the BTIFF in the BTIFF the image can be stored with the tiles organized horizontally or vertically this feature does not exists in TTIFF Because the TTIFF is now a standard for many image processing packages like XV for UNIX or ULEAD
36. ed lend line_spacing _ spacing between lines m 150 000000 log_vol_id product identifier string ERS2 SAR PRI projection BES eee a state vector nb_data_points number of the state vectors Inear_zero_fill_pixel_number number of filled pixels at start of each image line Inom_nb_looks_azim number of looks 3 000000 normalisation_ref_range eference slant range used for 847 000000 the spreading loss 168 BEST User Manual v4 0 2 pT eompensation km or Power or Complex image p Pulse Repetition Frequency 1679 902344 I prf equivalent f f internal TTIF flag 9 524895 oc r rf_equ roce ivalent i prochistory processing history sequence processing_paf identification of the processing IP present a processing system Din of the radar signal 0 056565 m power of the replica chirp 5464 1 000000 resolution unit internal TTIE flag BO row transient internal TIF flag OO sample_format format of the pixel 1 2 means integer 4 means floating point epresentation sample_per_pixel number of image layers Po sampling_rate sampling frequency in range 18 959999 MHz scaling factor internal TTIF flag 000000 RBIT 1508 FRAME 2547 second_of_day second in the day of the first state vector s flag indicating if the spreading loss compensation has been applied 1 means applied first line first pixel corner in the entire image coordinate system column valu
37. files are available for download from the ESA website http earth esa int services auxiliary_data asar If a product was acquired before the creation date of the latest applicable XCA file then it could have been processed with an older XCA file The calibration would be more accurate if the data were to be retro calibrated using the latest pattern If a product was acquired after the creation date of the latest applicable XCA file then there should not be any need for retro calibration The IMAGE RETROCALIBRATION tool is applicable only to ASAR detected ground range products which have the antenna pattern already applied and annotated and have been previously converted into power units The output image may have either a linear or dB scale It is also possible to apply a user generated antenna pattern AOI specification is permitted Example INI file IMAGE RETROCALIBRATION Input Dir G backscattering power Output Dir G backscattering out Input Image power_IMP4399 APf Output Image Scale LINEAR Output Image power_IMP4399 out Parameter Summary Image Retro calibration Input Image The name of the input power image in internal format Example Input Image power_IMP4399 APf mandatory INPUT BEST extensions APf XTf IT GT OV UNf DBf OP SGf SGc FI CR where indicates that it is
38. for Envisat products as in this case esp is always used to indicate ESRIN The number of tapes This will usually be 1 unless the Number Of Volumes 1 data is contained on more than 1 Exabyte tape The name of the output text file This will automatically be given the extension txt Annotation File header_IMP The name of the output Toolbox format file input for Header Analysis File header_IMP many other function This will be given the extension HAN This indicates that the volume drive would not be Dismount Volume N dismounted after the operation had finished Quick Look The QUICK LOOK tool generates directly from the original product a TIFF file of selectable size showing a subsampled approximation of the detected SAR scene The ASCH ini file generated to run the tool may look something like this OUICK LOOK Input Dir C BEST_out Output Dir C BEST_out Input Media Path D data ASAR DS1 ASA_IMP_1P 320 N1 Input Media Type cdrom Header Analysis File header_IMP HAN Output Quick Look Image ql_IMP Output Grid Image qlg_IMP Quick Look Presentation GEOGRAPHIC Number of Grid Lines 2 2 Output Image Size 800 0 Window Sizes 3 3 Grid Type LATLON Grid Drawing Mode transparent Min Percentage 1 Max Percentage 99 Dismount Volume N Supposi
39. g XV on Solaris2 ulead on PC Important It is not possible to open the TIFF files generated by BEST with all image viewing software For PC platforms you should not encounter any problems using Adobe Photoshop Jasc Paint Shop Pro or Microsoft Paint a standard component of Microsoft Windows found in the Start Menu under Programs gt Accessories gt Paint For Solaris2 platforms using XV it is necessary to launch the software first and then load the image from the browser 35 HMI best W Quick Look Input Media Type CDR Disk C Tape File Input Media Path Sc v gt Header Analysis File Sc be m Output Bc k Quick Look Image qLWSM tif Grid Quick Look glg WSM tif m Parameters record file name ini file parameters Jini OK Quit BEST User Manual v4 0 2 2 5 x m Quick Look Presentation Normal satellite geometry Geographic Number of Grid Lines fe Row B Column Output Image Size 800 Row fo Column Window Sizes B Row 3 Column Grid Type C RowCol LatLon Grid Drawing Mode Overwrite Transparent None Acknowledge Mount Yes No Rough Range Calibration IV Apply Show default values Typical HMI settings for an ASA_WSM_IP product copied to the hard disk Notes Select the product by means of the Input Media Path and the Header Analysis File
40. handling It is recommended that this processing chain is performed only for sub scenes 92 BEST User Manual v4 0 2 Example INI file SLANT RANGE TO GROUND RANGE CONVERSION Input Dir C BEST_out Output Dir C BEST_out Input Image asar_ims XTt Output Image sl2gr Delete Input Image N Parameter Summary Slant Range to Ground Range Conversion Input Image The complex or real image in slant range to be reprojected Example Input Image asar_ims XTt mandatory INPUT BEST extension XTt CRc CHf ML CAf APf OPc OPf BSP or GAP AOI specification see Appendix 4 for polygonal AOIs the surrounding rectangular AOI is used optional parameter default is entire input image Output Image The name of the output ground projected image an extension SGf or SGc is automatically added by the system Example Output Image sl2gr mandatory OUTPUT BEST extension SGf or SGc 93 BEST User Manual v4 0 2 Flip Image Description The FLIP IMAGE function performs a simple affine transformation on an image in the internal Toolbox format to render it in a recognisable form without running the Geo correction tool The ASAR Toolbox automatically locates the first pixel of the first line of a data set in the top left corner of the image In reality the first data sample is located in the
41. image For single look data the software performs nominal multi looking in the azimuth direction unless both axes are constrained by the user The output image is generated in two forms one clean and the other with a grid superimposed to help locate a scene and retrieve coordinates for points within the image The two coordinate systems in which the grid can be generated are row column and latitude longitude Important When starting from data in an internal format file the data may or may not contain the required ancillary geolocation parameters If these parameters are not present this will be the case if the image is the output from the IMPORT RASTER IMAGE function of the Data Import tool the grid can be drawn only in row column coordinates The quick look image can be displayed in a geometric orientation option GEOGRAPHIC i e so that north is up south is down west is left and east is right or in an orientation as viewed by the satellite option NORMAL A rough range calibration may also be applied during the quick look generation to account for variation of incidence angle across the swath width Whilst the aesthetic improvement is most noticeable in Wide Swath and Global Monitoring Mode products the option is available for all ASAR and ERS data except geocoded products 1 e ERS GEC and GTC ASAR APG and IMG The output image is stored in standard TIFF format so it can be read using any TIFF reader e
42. of two or more real or complex images including ERS Envisat pairs evaluation of quality parameters geometric correction of medium resolution products Support for Interferometry computation of orbital baseline from DORIS files calculation of interferometric coherence evaluation of altitude of ambiguity Speckle Filtering removal of speckle noise from a backscatter image Calibration radiometric correction of Envisat and ERS images including retro calibration of ASAR products and wide swath image refinement BEST User Manual v4 0 2 Running BEST The algorithms of the Toolbox are executed by means of the Human Machine Interface HMI Users are able to specify parameters select input files and name output files according to the selected algorithm For Windows users there is a familiar Visual Basic interface The HMI for LinuX and Solaris2 users is written in Tcl Tool Command Language The Tcl Tk software must be installed prior to running BEST on these platforms Both HMIs essentially automate the generation and execution of ASCII ini files that are required by the Toolbox However it is perfectly possible to use the Toolbox without an HMI Some users may prefer to produce their own ini files or edit existing ones to meet their specific needs and run these directly from the command prompt To execute a tool type the command BEST file_name ini where file_name ini is an ASCII file containing the
43. parameters necessary for a tool s execution For processing data using a series of tools it is possible to edit ini files together into a macro ini file so that the entire procedure may be executed by a single command Later in this section three simple examples are presented which describe in detail the various parameters of ini files required to run some basic Toolbox functions What data can be read The Toolbox has been designed to handle ESA data products from both the Envisat ASAR instrument and the AMIs on ERS 1 amp 2 ASAR data acquired in Image Mode Wide Swath Mode Alternating Polarization Mode and Global Monitoring Mode processed to Level 1b SLC Precision Medium Resolution or Ellipsoid Geo coded is supported Image Data from ERS SAR processed as RAW SLC SLCI PRI GEC or GTC is also supported The Toolbox handles the standard Envisat product file format For ERS data products generated within the ESA ERS Ground Segment at D PAF I PAF UK PAF and ESRIN are supported plus data from many of the foreign stations in the following formats e ESA CEOS version 3 0 used by all ESA PAFs since January 1997 e ESA CEOS version 2 1 used by ESA PAFs from October 1995 to January 1997 also used by several foreign stations e g China South Africa Argentina Singapore e ESA CEOS version 2 0 used by several foreign stations e g Ecuador BEST User Manual v4 0 2 Toolbox formats and file e
44. processing software packages The process maintains the pixel format and therefore the accuracy of the source data The conversion generates an output image file with the extension BG an associated ASCII header file with the extension ers and a text file containing the annotations of the first input image with the extension txt The ers file is not generated if the inputs are complex images No AOL is permitted in this conversion For a data set of z bands with dimensions y rows and x columns the data in the binary file will be arranged as follows band 1 row 1 pixel 1 band row band 2 row 1 pixel 1 band row band z row 1 pixel 1 band row band 1 row 2 pixel 1 band row band 2 row 2 pixel 1 band row band z row 2 pixel 1 band row band 1 row y pixel 1 band row band 2 row y pixel 1 band row band z row y pixel 1 band row Example INI files BIL GENERATION Input Dir C BEST_out Output Dir C BEST_out Input Images input XTs Output Image output Output Annotations File output_annot The following example uses 4 input files BIL GENERATION C BEST_out Input Dir Output Dir Input Images Output Image Output Annotations File bandl_annot C BEST_out pixel pixel pixel pixel pixel pixel pixel pixel pixel
45. rectangular grid but their positions may also be specified by the user in an ASCII file defined using the parameter GCPs File Name see below in the paragraph Specified GCPs The number of rows and columns in the automatically derived grid defined on the master image is determined by the parameter GCPs Numbers the total number of GCPs being the product of the two dimensions Coarse Registration Step step 2 A coarse registration step is performed using a cross correlation operation on a series of cells centred on the GCPs see above defined across the master image For both real and complex images the coarse registration step can be switched on or off using the flag parameter Image Coarse Reg 114 BEST User Manual v4 0 2 The size of the coarse registration cells is defined by the parameter Coarse Reg Window Sizes In general the larger is the cell window size the longer will be the program running time The accuracy and program running time for the coarse registration step is also determined by the parameter Coarse Reg Interp Factors This parameter sets the row col interpolation factors for the coarse registration step The units are pixel and this parameter defines the step size used in the cell cross correlation process Higher values produce good accuracy at the expense of longer running time A check on the accuracy achieved by the coarse registration step is performed for each GCP cel
46. shell Create a home directory for BEST mkdir BEST Decompress the g zipped tar file after moving it to the directory previously created tar xvfz software tar gz This will extract the ready compiled BEST executables into the bin directory and the BEST shared library into the lib directory If the login shell is the C shell or tesh see 1 above modify or build the cshrc file found in the user s home directory with the following lines setenv BESTHOME BEST lt the home directory path see 2 above setenv FLAGFILE SBESTHOME flagfile setenv PATH BESTHOME bin SPATH If the login shell is the Bourne Again shell see 1 above modify or build the bashrc file found in the user s home directory with the following lines BESTHOME BEST lt the home directory path see 2 above FLAGFILE SBESTHOME flagfile PATH SBESTHOME bin SPATH export BESTHOME FLAGFILE PATH If the login shell is the Bourne or Korn shell see 1 above modify or build the profile file found in the user s home directory with the following lines BESTHOME BEST lt the home directory path see 2 above FLAGFILE SBESTHOME flagfile PATH SBESTHOME bin SPATH export BESTHOME FLAGFILE PATH Exit from the current shell and create a new one BEST is then ready to be run
47. tape cdrom or disk DOP 2207 NIS 220 IF Input Media Type is file where indicates output from any BEST tool except Data Export tools 37 BEST User Manual v4 0 2 Header Analysis File The internal format file containing all the decoded annotations obtained during the HEADER ANALYSIS operation on the same product with the associated extension HAN The parameter is ignored IF Input Media Type is file the header data comes from the internal image format annotations Example Header Analysis File header_WSM HAN mandatory INPUT IF Input Media Type is tape or cdrom BEST extension HAN Output Quick Look Image The name to be given to the standard TIFF file containing the quick look image stretched to 8 bit and without a grid annotation an extension tif is automatically added by the system Example Output Quick Look Image ql_WSM mandatory OUTPUT BEST extension tif Output Grid Image The name to be given to the standard TIFF file containing the quick look image stretched to 8 bit and annotated with a grid an extension tif is automatically added by the system Example output Grid Image qlg_WSM mandatory OUTPUT BEST extension tif Quick Look Presentation The orientation of the output image GEOGRAPHIC with north at the top south at the bottom west to the left and east to the right
48. the input master image over which the slave image s must be co registered Example Input Master Image asar_aps XTt mandatory INPUT BEST extension 7 22s 22t 2 f or c where indicates that any BEST module could have produced these files Input Images The name of the input slave image s to be co registered and superimposed Example Input Images slave_1 XTt slave_2 XTt mandatory INPUT BEST extension 731 27 77 2 P 22c where indicates that any BEST module could have produced these files Output Image Size The size of the output TIFF image that contains the master image superimposed with the slave s outlines expressed in row col Example output Image Size 1485 490 To maintain the aspect ratio of the input data set one of the values to 0 This causes the system to compute a size that maintains square pixels To generate an output image with 1400 rows and square pixels use Output Image Size 1400 0 To generate an output image with 500 columns and square pixels use Output Image Size 0 500 mandatory parameter default is 1000 0 126 BEST User Manual v4 0 2 Output Image The name of the output file that contains the footprint co registration image the extension tif is automatically added by the system Example output Image footprint mandatory OUTPUT BEST extension tif 127 BEST User Manual v4
49. this is the case for the following SAR products e SAR products delivered by CRISP processor located at Singapore station e SAR products delivered by ACS w k processor located in Argentina Cordoba China Beijing Ecuador Cotopaxi Israel Tel Aviv Kenya Malindi Russia South Africa Thailand Bangkok The HEADER ANALYSIS module checks that images are generated from ESA products This is done by testing that the log_vol_gen_agency tag is exactly ESA except on Singapore products for which log_vol_gen_agency tag has to be exactly CRISP Important The output file in the Toolbox internal format which has the extension HAN is a necessary input to the FULL RESOLUTION EXTRACTION and QUICK LOOK GENERATION functions unless Input Media Type is set to file for the latter 28 BEST User Manual v4 0 2 HMI Fe r Input Product Qa Input Media Type CDR Tape Hard Disk ASA IMS 1PNUPA20050116 154942 000000162033 00484 15067 0960 N1 Sensor Id C ERSA SARA ERS 2SAR de Envisat ASAR Sensor Mode Image Global Monitoring Wide Swath Alternating Polarization Altemating Polarization Dataset ei aye Product Type C PRI de SLE SLC GEC GIE C MRA C BRW C Raw Data Data Format CEOS MPHSPH Source Id f ESRIN PAF CO UKPAF D PAF C Foreign Stations Singapore Station Number of Volumes fi Acknowledge Mount Y CN r Output Sc al Annotation Fi
50. to obtain a more smoothed image Example Window Size 3 3 mandatory parameter Grid Type The type of grid lines to be used ROWCOL rows and columns LATLON latitude and longitude Example Grid Type LATLON mandatory parameter Grid Drawing Mode The drawing style for the numerical grid labels overwrite gives the labels a black background transparent only the text itself obscures the underlying image none no labels are written on the image Example Grid Drawing Mode transparent mandatory parameter Rough Range Calibration An optional flag to invoke approximate correction of intensity across the image swath caused by incidence angle variation Example Rough Range Calibration APPLY optional parameter calibration only applied if present Acknowledge Mount This parameter is used to avoid the request to acknowledge the unit mount during the quick look generation To execute a header extraction immediately followed by a quick look generation using a unique ini file set Dismount Volume N in the HEADER ANALYSIS module and set Acknowledge Mount N in the quick look module HEADER ANALYSIS Dismount Volume N OUICK LOOK Acknowledge Mount N This parameter is ignored i e is assumed Y for multi volume processing optional parameter default is Y Dismount Volume A flag indicating whether the media shall
51. window of a user defined size which moves with a step size of 1 pixel across the images The input data must be complex or real in the Toolbox internal format and with floating point pixels Images cannot be input if they have been extracted directly from SAR products in which case the pixel has an integer or complex integer format Complex data are processed by evaluating the modulus of the complex correlation coefficient only the real correlation coefficient is considered for real images The coherence generation function produces an output image with the same size as the input couple Note that there will be an edge effect caused by the size of the moving window in which the coherence is calculated This effect will cause a buffer of pixels with a depth equal to half the window size to be set to zero at the edges of the output image Example INI file COHERENCE IMAGE GENERATION Input Dir m t Output Dir Input Images slc_master CRc slc_slave CRc Output Image cohe Window Sizes 7 7 Parameter Summary Coherence Generation Input Images The name of the input image couple in internal format from which the coherence is generated Example Input Images mas CRc sla CRc mandatory INPUT BEST extension f c where indicates it is not important which module created the files as long as the data type is correct AOI specification see Appendix 4
52. 0 2 Speckle Filtering tool 1 Speckle Filter Removes speckle noise from real intensity images using the Gamma MAP algorithm Calibration tools For ERS data 1 Backscattering Image Generation Converts a power image into a backscatter image 2 ADC Compensation Corrects a power image for the ADC saturation phenomenon in ERS SAR products prior to BACKSCATTERING IMAGE GENERATION 3 Gamma Image Generation Converts a backscatter image i e output from BACKSCATTERING IMAGE GENERATION into a Gamma image by dividing by the cosine of the incidence angle For ASAR data 4 Backscattering Image Generation Converts a power image into a backscatter image 5 Retro calibration Removes an annotated antenna pattern and replaces it with another one 6 Rough range Calibration Corrects ASAR Wide Swath and Global Monitoring Mode images for the effect of incidence angle variation from near to far range 7 Enhancement Swath Corrects ASAR Wide Swath and Global Monitoring Mode products affected by intensity discontinuities between sub swaths 4 BEST File Extensions and Internal Format BEST User Manual v4 0 2 The BEST output file extensions are designed to show which tool has created them and the type of data that they contain The extension usually includes two upper case letters followed by a lower case letter The upper case letters indicate the Toolbox function e g PA Power to Amplitude Conversion The lower case let
53. 4 4 METER EUPEEUPEEUEEEPENEPEEEPEREEEI E PEEP PEEEEEEPEEEEEEEEEEEEI BERERESESREREREREE Set WERERBEREREREREREE st A minimum overlap zone maximum overlap zone master overlap zone 118 BEST User Manual v4 0 2 Baseline Calculation For real or complex images the baseline between the two satellites is calculated using the orbit information and the warp function The baseline is evaluated at the scene centre both the normal and parallel components in the same coordinate system that the orbit is given for each slave image It is possible for the user to specify the name of the text file that will contain these values using the parameter Baseline File Name The following example shows the format of the baseline file for a single slave image Slave number 1 Baseline Cartesian Components in meters X Y Z 30 535631 60 703657 19 806008 Baseline Components in the Sat Target Plane in meters Normal Parallel 62 978227 32 301387 Example INI files The following ini files are examples for the CO REGISTRATION tool Two cases are shown the most basic with the minimum set of parameters and a more complicated one with customised configuration parameters MAGE CO REGISTRATION put Dir C BEST_out t Dir C BEST_out t Images slc_master XTt slc_slave xXTt tput Images master slave OHOH GPG H ct Ss c IMAGE CO REGISTRATION nput Dir C BEST_out ut
54. Annotation name Meaning Example value absolute_calib_k calibration constant value 999978 000000 linear adc_satur_compens_flag flag indicating if the ADC saturation compensation has been applied 1 means applied antenna_elevation_gain_flag flag indicating if the antenna pattern correction is apllied 1 bits_per_sample the number of bits of the pixel eee 7 bottom _left_lat latitude of the last line first RE lemme capes pixel corner degree corner degree bot longitude of the last line last pixel corner degree flag indicating if the spreading calibtration constant has been internal TTIF flag OT internal TTIF flag 5 MM cross_dopp_freq_const doppler frequency polynomial 150 656296 order 0 coefficient Hz 167 BEST User Manual v4 0 2 order 1 coefficient Hz s order 2 coefficient Hz s s CEOS or MPHSPH vector disposition intemal TTIE flag early_zero_fill_record_numb er number of fill lines at image start ellipsoid_semimajor_axis ellipsoid semimajor axis km 6378 144043 ellipsoid_semiminor_axis ellipsoid semiminor axis km 6356 758789 pee pee ed leach image line gr_sr_coeff_1 slant to ground polynomial 0 000969 FE a ee gr_sr_coeff_2 slant to ground polynomial 526 446899 GE eee eee gr_sr_coeff_3 slant to ground polynomial 11 997012 eee eed gr_sr_coeff_4 slant to ground polynomial 0 061625 Ce Damen coeffient 5 degree image LINEAR or DB scale image degrre BE ee
55. BEST extension ascii input file Output Image The name of the translated file to be written in the Toolbox internal format an extension SDf is automatically added by the system 48 BEST User Manual v4 0 2 Example Output Image ersl_antpat mandatory OUTPUT BEST extension SDf 49 BEST User Manual v4 0 2 Import GeoTIFF Description The IMPORT GEOTIFF tool converts a GeoTIFF image including its associated annotation data into the BEST internal format Important The following functions cannot be applied to data converted using the IMPORT GEOTIFF tool OVERSAMPLING CO REGISTRATION SPECKLE FILTER the Calibration tools and the Data Conversion tool except GEOMETRIC CONVERSION at lon row col and ANCILLARY DATA DUMP No AOL is permitted in this operation Example INI file IMPORT GEO TIFF Input Dir C BEST_out Output Dir C BEST_out Input Image mr_gtif tif Output Image int_gtif Delete Input Image N Parameter Summary Import GeoTIFF Input Image The external GeoTIFF image Example Input Image mr_gtif tif mandatory INPUT BEST extension tif Output Image The name of the output internal format file that contains the input image and annotations Example output Image int_gtif mandatory OUTPUT BEST extension GT where indicates that the output image retains the same format as the input image 50 BEST User
56. Cesa sru c telespazio BEST Basic Envisat SAR Toolbox User Manual Version 4 0 2 March 2005 Please report bugs to eohelp esa int Find further BEST information at http envisat esa int best BEST User Manual v4 0 2 This User Manual is a work in progress You are invited to check the website regularly for updated versions BEST User Manual v4 0 2 Contents A OVERVIEW A 4 1 Intreduelone see en Rn ep aae ee fey oe ren ee 5 2 Three Simp les Examples 2 22 each enter 8 5 BEST Funchons Summary teaser ea kei eg ilekeliene 12 4 BEST File Extensions and Internal Format Beeren u ek 16 5 Installation2 Heisei inci ie eg ER SH 18 Ge HMI t ctonality cenene nenn a a a a a a n a ana 23 Jat Li E TETT 25 7 Data Import and Quick LOOK u a ara 26 leader FN TVA Y S18 oss E wade saunas ces woes sacs a Sr es ee Se ee es 28 Media Analyssyr a na SE EEE tke 33 Quick Look Generalo marerena EHAGRe He 35 Full Resolution Prtraeton ea een kg 40 Portion Extraction a coos ia estes shhh ae shay A Geshe bde HO ase GORE ee Ue tia aes 43 Ena ta KAER TEVA we ee eee See 45 Coordinates Retrieving by Example Image eee cessscccceeceeeeseeennceeeeceeeeseeennnaeeeeeeees 46 Support Data Ingestion u 2 a3 ieehkanaahiauklkia lau a 48 Import Geo FIEF jases TERUEERL BEBBRLLTERVERDEITERERUEHDERLTEENDEFHEUESEEHETDEIBEBELTETDERCRLTTEEREILTERSERRR 50 Import MEPE ennestaan E 51 Import Raster magens aatis ania ah iiaia eain 52 New Prod
57. EST extension tif 64 BEST User Manual v4 0 2 Export to TIFF Description The EXPORT TO TIFF function converts an image in the internal BEST format to a universally readable TIFF format A standard grey level TIFF image can be generated from data of any type handled internally by the Toolbox i e 8 bit integer 16 bit integer floating point or complex pixels An RGB colour TIFF image can be generated from three 8 bit images The TIFF version for such export is TIFF6 An ASCII file containing the image annotations is also generated as an output No AOL is permitted in this operation Important If the image viewer XV is used to visualise the output from the TIFF conversion module it may be necessary to first launch the XV software and then load the image using the internal commands rather than using for example the command xv grey_img tif This is because of the nature of the TIFF file generated by the Toolbox module Example INI files The following ini file is an example for grey level TIFF image generation TIFF GENERATION Input Dir C BEST_out Output Dir C BEST_out Input Images asar_apm XTs Delete Input Image N Output Image apm tif Output Annotations File anno_tif The following ini file is an example for 3 colour TIFF image generation TIFF GENERATION Input Dir C BEST_out Output Dir C BEST_out Input Images red
58. Example Output Images masr slalr sla2r sla3r mandatory OUTPUT BEST extension CRf or CRc Baseline File Name The name of the text file which will contain the baseline information evaluated for each slave image Example Baseline File Name basel_values txt optional OUTPUT default is baseline txt Image Coarse Reg Determines whether the 2 coarse registration step should be performed on the data Example Image Coarse Reg N optional parameter default is Y GCPs Numbers The number of GCPs that will be used in the co registration defined by the dimensions of a grid expressed in row col The cells will be generated at the intersections of the grid This parameter is ignorred when the GCPs File Name is defined Example GCPs Numbers 7 5 optional parameter default is 10 10 GCPs File Name The name of a text file containing user selected GCPs expressed in row col full resolution coordinates on the master image for use in the co registration process This parameter defines an alternative to the GCPs generated automatically if the parameter GCPs Numbers is defined If the parameter is not defined GCPs are generated automatically according to the GCPs Numbers parameter Example GCPs File Name GCPFile dat optional INPUT Editing RMS 120 BEST User Manual v4 0 2 The threshold in units of pixels to exclude from the warp function those GCPs that produce
59. Example Replica Power Correction APPLY optional parameter default is no correction ADC Saturation Correction Determines whether the ADC saturation compensation factor shall be applied APPLY if the parameter is omitted no correction is considered this correction cannot be removed from the image Example ADC Saturation Correction APPLY optional parameter default is no correction ADC Saturation Correction File The name of the internal format file containing the ADC saturation correction image generated using the ADC CORRECTION image generation tool Example ADC Saturation Correction File adc ADf mandatory INPUT if ADC Saturation Correction is set to APPLY BEST extension ADf Calibration Constant Correction Determines whether backscattering values shall be computed from an input power image APPLY or if the inverse transformation from backscattering image to original power image shall be applied REMOVE if the parameter is omitted no transformation is performed neither in one direction nor in the other Omitting the parameter allows one or more correction factors to be applied to the input image without altering the image type Example Calibration Constant Correction APPLY optional parameter default is no change to image type 146 BEST User Manual v4 0 2 Calibration Constant A user defined value for the calibration constant if missing the value contained in t
60. First Zero Doppler Azimuth time of produ 22 JAN 2005 09 55 56 5170 UTC zero_dopp_azim_first_time UTC of 1st range line in the M ct 81 DS of this product 11 Last Zero Doppler Azimuth time of produc 22 JAN 2005 09 56 12 7908 UTC zero_dopp_azim_last_time UTC of last range line in the t 31 MDS of this product 14 Geodetic latitude of the first sample at 0043932217 10 6 deg top_left_lat E the first line 18 East geodetic longitude of the first sam 0006346123 10 6 deg top_left_lon ple of the first line 21 Geodetic Latitude of the middle sample o FIRST_MID_LA f the 1st line lt 10 6degN gt 22 East geodetic longitude of the middle sa FIRST_MID_LONG 000565383 10 6 deg mple of the first line 5 lt 10 6degE gt 24 Geodetic Latitude of the last sample of 0044132757 10 6 deg top_right_lat a the first line 28 East geodetic longitude of the last samp 0005060429 10 6 deg top_right_lon le of the first line 32 Geodetic Latitude of the first sample of 0042977177 10 6 deg bottom_left_lat ad the last line 36 East geodetic longitude of the first sam 0006045342 10 6 deg bottom_left_lon ple of the last line 39 Geodetic Latitude of the middle sample o LAST_MID_LAT 0043086310 lt 10 6 deg T f the last line 10 6degN gt 40 East geodetic longitude of the middle sa LAST_MID_LONG 0005365082 mple of the last line lt 10 6degE gt 42 Geodetic Latitude of the last sample of 0043176387 10 6 d
61. G BY EXAMPLE IMAGE function a warning message is issued explaining that it will not be possible to retrieve the full resolution coordinates In such cases try another image processing system Typical Processing Chain HEADER ANALYSIS gt QUICK LOOK GENERATION cropping using external tool gt COORDINATES RETRIEVING BY EXAMPLE IMAGE Example INI file COORDINATES RETRIEVING Input Dir C BEST_out Output Dir C BEST_out Input Image quicklook tif Cropped Tiff Image example tif Output Coordinates File coords Parameter Summary Coordinates Retrieving by Example Image Input Image The original quick look image with or without grid in standard TIFF format Example Input Image quick look tif mandatory INPUT 46 BEST User Manual v4 0 2 BEST extension tif Cropped Tiff Image An example image cropped from the original quick look image in standard TIFF format Example Cropped Tiff Image example tif mandatory INPUT BEST extension tif Output Coordinates File The name of the output text file that will be written with the row column coordinates of the Top Right and Bottom Left corners of the example image expressed in the full resolution coordinate system an extension txt is automatically added by the system Example Output Coordinates File coords mandatory OUTPUT BEST extension txt 47 BEST User Manual v4 0 2 Support Data Ingesti
62. Header Analysis Input Media Path The path of the media unit fora PC CDROM use Input Media Path D data ASAR DS1 ASA_IMP_1P 320 N1 fora Unix EXABYTE device use Input Media Path dev rst1 for a Unix CDROM device use the entire path to the selected scene ERS SAR product CDROMs can have multiple scenes on them Input Media Path cdcom SCENE1 mandatory INPUT BEST extension data product Input Media Type The source media of the product tape Exabyte cdrom disk hard disk Example Input Media Type cdrom mandatory parameter 30 BEST User Manual v4 0 2 Sensor Id The platform from which the data was acquired ers ers ASAR Example Sensor Id asar mandatory parameter Sensor Mode The mode in which Envisat ASAR data was acquired Image IM Wide Swath WS Global Monitoring GM Alternating Polarization AP note spelling with a z Example Sensor Mode Image mandatory parameter IF Sensor Id is ASAR AP Dataset The channel of an Envisat ASAR Alternating Polarization product to process selectable between MDS1 or MDS2 Example AP Dataset 1 mandatory parameter IF Sensor Id is ASAR AND Sensor Mode is Alternating Polarization Product Type The type of data product PRI Precision products IMP APP MR Medium Resolution products
63. Image pri APf 148 BEST User Manual v4 0 2 RMS Window Size 8 8 PRI Smoothing Window Size 400 1200 SLC Smoothing Window Size 630 1280 Reference Replica Power 205229 0 156000 0 Reference Chirp Average Density 267200 201060 Output Image pri_adc Parameter Summary ADC Compensation Input Image The name of the input image in internal format containing intensity power data from which the ADC compensation image will be generated The image shall be the same or contain the image used for the subsequent backscattering image generation Example Input Image pri APf mandatory INPUT BEST extension APf Calibration Constant A user defined value for the calibration constant if missing the value contained in the image annotations is used Where used this parameter must be the same as that specified in the subsequent backscattering image generation Example calibration Constant 9500000 0 mandatory parameter IF the calibration constant is specified in the subsequent backscattering image generation RMS Window Size The size of the RMS averaging filter used to reduce the input image for computational efficiency in row col Example RMS Window Size 8 8 mandatory parameter Output Image The name of the output image in internal format containing the backscatter data the extension ADP is automatically added by the system Example Output Image pri_adc mandatory OUTPUT BEST extension
64. Manual v4 0 2 Import TIFF Description The IMPORT TIFF tool converts an image in standard TIFF format to the Toolbox internal format Any annotations written in a separate text file are inserted into the output internal format image The data to be converted can be initially present on the hard disk or another media thus avoiding the need to dump the image using the operating system commands Example INI file IMPORT TIFF Annot Input Dir C BEST_out Input Annotation anno_tif txt Input Dir C BEST_out Input Image ext_tif tif Output Dir C BEST_out Output File imp_tif Delete Input Image N Parameter Summary Import TIFF Annot Input Dir The path to the directory that contains the annotation file if one exists Example Annot Input Dir mandatory INPUT Input Annotation The name of the text file that contains any annotation to be inserted into the output internal format image Example Input Annotation anno_tif txt mandatory parameter Input Image The external image in a standard TIFF format Example Input Image ext_tif tif mandatory INPUT BEST extension tif Output File The name of the output internal format file that contains the input image and annotations Example Output File imp_tif mandatory OUTPUT BEST extension IT where indicates that the output image retains the same format as the input image 51 BEST Use
65. NORMAL in an orientation as viewed by the satellite Example Quick Look Presentation GEOGRAPHIC optional parameter default is GEOGRAPHIC Number Of Grid Lines The number of iso row or iso latitude lines and iso column or iso longitude lines in the grid annotation the first number refers to iso row or iso latitude lines at least one of number shall be greater than zero Example Number Of Grid Lines 8 8 mandatory parameter Output Image Size The number of rows and columns in the output quick look image the first number indicates the number of rows Example Output Image Size 800 800 To maintain the aspect ratio of a multi looked input image or perform nominal multi looking on a single look input image set one of the values to 0 This invokes the system to compute an appropriate length for the second axis based on the single dimension defined To generate a quick look image of a multi looked input with 500 rows and square pixels use Output Image Size 500 0 To generate a quick look image of a single look input with 600 columns and nominal multi looking in the azimuth direction use Output Image Size 0 600 mandatory parameter 38 BEST User Manual v4 0 2 Window Size The number of rows and columns in the moving window used to average the full resolution data during the quick look creation the first number indicates the number of rows Use 1 for a pure sub sampling and a greater number
66. OUTPUT BEST extension txt Header Analysis File The name to be given to an internal format file that will contain all the decoded annotations for use in subsequent processing an extension HAN is automatically added by the system Example Header Analysis File header_IMP mandatory OUTPUT BEST extension HAN Dismount Volume A flag indicating whether the media shall be dismounted from the unit at the end of the volume processing shall be set to N when a series of repeated extraction operations are planned on the same cassette thus avoiding repeated unit mounting This parameter is ignored i e is assumed Y for multi volume processing Example Dismount Volume N optional parameter default is Y 32 BEST User Manual v4 0 2 Media Analysis Description The MEDIA ANALYSIS function determines from a product held on Exabyte tape the number of files in each volume the number of records in each file and the number of bytes in each record Important Media analysis is only possible for data on Exabyte it will not work for data on CDROM The information extracted by the MEDIA ANALYSIS function is stored in a file called the Media Content Report output MCR file and can be used for the following two purposes 1 The media content report contains a clear summary of the product s physical structure and can therefore be used to quickly check that the data on the tape corresponds to its lab
67. R where indicates that it is not important what format the data is in Output Image The name of the output image in internal format containing the rough range calibrated data the extension X7f is automatically added by the system Example output Image WSM_rough mandatory OUTPUT BEST extension XTf 155 BEST User Manual v4 0 2 Swath Enhancement ASAR Description The SWATH ENHANCEMENT tool enables the user to correct ASAR Wide Swath and Global Monitoring Mode products affected by intensity discontinuities between sub swaths The resulting image will not be radiometrically sound but gives a more aesthetically pleasing appearance The tool applies a linear coefficient named Gain to each of the five sub swaths of the image Both the Gains and the range limits of each sub swath in terms of their end column must be provided by the user By virtue of the ScanSAR acquisition process Wide Swath and Global Monitoring Mode products are made up of five independent swaths of imagery that may exhibit differing radiometry Here a methodology is suggested for manually evaluating a WS image to characterise the inter swath differences and determine the gain values required by the tool e First select arbitrarily a master sub swath for which the gain value is set to one e Than using image processing software find the relative intensity a ratio of the other sub swaths by averaging over a hom
68. The statistical parameter that is computed for each position of this kernel is used to build up an output image that presents information about the local statistics of the input image The statistical parameters available are the mean standard deviation coefficient of variation and equivalent number of looks It is possible for the user to specify the size of the kernel in which the statistical parameters are calculated It is also possible for the user to specify the step size that determines the frequency with which the statistical parameter is calculated These step sizes will also determine the size of the output image The user can also define the output image size by specifying the Output Image Ratio values along the rows and columns see the second example INI file below The area of interest AOI of the input image can be specified in any way except the example image mode including polygonal AOI When the kernel is partly or completely outside the AOI no statistics are generated For more details see the Statistical tools chapter of the Algorithm Specification Document A3 Example INI files LOCAL STATISTIC Input Dir Output Dir Input Image tl_priimage XTs Filler Value 0 0 Coordinate System ROWCOL Top Left Corner 100 100 Bottom Right Corner 500 500 Output Image Type MEAN window Sizes 5 5 window Steps 2 0 2 0 Output Image tl_locstatmean In
69. UTION EXTRACTION and QUICK LOOK GENERATION tools Also writes the header information to an ASCII text file for reference purposes 2 Media Analysis Determines the number of files in each volume the number of records in each file and the number of bytes in each record for products held on Exabyte media 3 Quick Look Generation Generates a reduced resolution approximation of an image directly from the original data product or from an internal format file 4 Full Resolution Extraction Extracts a full resolution portion of an original data product to the internal file format 5 Portion Extraction Extracts a full resolution subset of an image already in the Toolbox internal format 6 Image Preview Extracts a region of interest from a quick look image This function is useful to verify that a region of interest is correctly defined before it is extracted at full resolution 7 Coordinates Retrieving by Example Image Derives the coordinates within a scene that define a subset or region of interest as extracted from a quick look image and saved as a second tif file using another image viewing tool 8 Support Data Ingestion Converts support data e g antenna pattern information or lookup tables for calibration from an ESA ASCII format into the Toolbox internal format 9 Import GeoTIFF Converts a GeoTIFF image into the Toolbox internal format 10 Import TIFF Converts standard TIFF files to the Toolbox internal format 11
70. Y RECORD 1 1886 Y RECORD 1 1620Y RECORD 1 1046Y RECORD 1 12288 Y FILE 3 Y RECORD 8201 16012 Y FILE 4 Y RECORD 1 360Y This entry describes a ERS1 PRI product of the Italian PAF kept on 1 Volume organized on 4 files file 1 has 4 records of 360 bytes each file 2 has 1 record of 720 bytes 57 BEST User Manual v4 0 2 1 record of 1886 bytes 1 record of 1620 bytes 1 record of 1046 bytes 1 record of 12288 bytes file 3 has 8201 records of 16012 bytes each file 4 has 1 records of 360 bytes All this information is used during the comparison of the media structure all flags are Y Following these rules it is possible to add new entries in the Nominal Media Structure File Format Description File description In order to have a tool independent from the product type PRI SLC GEC etc and media EXABYTE or CDROM to be de formatted a simple description language has been defined to describe the format of each product in a Format Description File FDF In this way a change of product format does not affect the source code of any module it is only necessary to properly update the FDF of the correspondent product type Note that this approach allows to handle in the same manner not only the CEOS format but also all the positional product formats for example the MPH SPH product format Each Product Annotation must be given an annotation name this name is used to find out the tags related to the annotation itsel
71. _data PAf Output Image power_data Paremeter Summary Amplitude to Power Conversion Input Image The name of the input real image in internal format Example Input Image ampl_data PAf mandatory INPUT BEST extension f 1 22s where indicates that any BEST module could have produced this file AOI specification see Appendix 4 for polygonal AOI the surrounding rectangular AOI is used optional parameter default is entire input image Output Image The name of the output image containing power data the extension APf is automatically added by the system Example Output Image power_data mandatory OUTPUT BEST extension APf 77 BEST User Manual v4 0 2 Linear to dB Conversion Description The linear to dB conversion function is used to convert an image an amplitude or an intensity image from the linear scale to a dB scale The AOI which are permitted are the rectangular AOI with corners expressed in row col system or in lat lon or even the polygonal AOI in this case the surrounding rectangular AOI is used No further parameter is needed Note that to convert a complex image into dB a modulus extraction shall be executed Example INI file LINEAR TO DB Input Dir Output Dir Input Image pwdata APf Output Image data_db Linear to dB Conversion Summary Table Example Input Image the name of the amplitude or power image in man
72. a is in Output Image Scale The scale of the output backscatter image LINEAR DB Do not use the dB scale if a further step of averaging is foreseen Example Output Image Scale LINEAR mandatory INPUT Calibration Constant A user defined value for the calibration constant if missing the value contained in the auxiliary file is used Example calibration Constant 34994 516 optional parameter Sensor Id 151 BEST User Manual v4 0 2 The platform from which the input data was acquired ERS ENVT Envisat Example sensor Id ENVI optional parameter Output Image The name of the output image in internal format containing the backscatter data an extension BSF is automatically added by the system Example Output Image bs_pow_IMP4399 mandatory OUTPUT BEST extension BSf 152 BEST User Manual v4 0 2 Image Retro calibration ASAR Description The IMAGE RETROCALIBRATION tool is used to remove an annotated antenna pattern and replace it with another one The function is useful in cases when routine instrument calibration exercises reveal that the antenna pattern for recently acquired data could be better estimated with a new pattern In such cases ESA generates a new External Calibration File XCA which may supersede one used to process a certain product originally The XCA file used to process the product is annotated in the SPH The most recent XCA
73. ample above the algorithm assumes that all the input values greater than the last present in the lookup shall be set to 255 So in the example above all pixels in the input image with values greater than 2000 are set to 200 72 BEST User Manual v4 0 2 Look Up Table Format for Gain Conversion Example 2 060 100 200 300 500 800 1000 2000 The lookup corresponding to this figure above is 30 300 50 500 80 800 120 1000 Notice how the input values greater than 1000 are automatically set to 255 73 BEST User Manual v4 0 2 Typical Processing Chain HEADER ANALYSIS gt FULL RESOLUTION gt GAIN CONVERSION gt TIFF GENERATION Example INI files The following INT file is an example for the gain conversion with fixed gain GAIN CONVERSION Input Dir Output Dir Input Image tl_priimage XTs Top Left Corner 0 0 Bottom Right Corner 799 799 Output Image fixgain The following INT file is an example for the gain conversion with variable gain GAIN CONVERSION Input Dir Output Dir Input Image tl_priimage XTs Top Left Corner 0 0 Bottom Right Corner 799 799 Min Percentage 0 1 Max Percentage 99 8 Number of Black Levels 1 0 Output Image vargain The following INT file is an example for the gain conversion with lookup table GAIN CONVERSION Input Dir Output Dir Input Image tl_priimage XT
74. andatory INPUT BEST extension any internal Toolbox format file Output File The name of the output file containing the values of the sensitivity vector calculated for the specified points The extension txt is automatically added by the system Example output File sns_vect Mandatory OUTPUT BEST extension txt Input Coordinates Type The manner in which points shall be defined ROWCOL one by one by rows and columns LATLON one by one by latitude and longitude POINTGRID define an equally spaced grid Example Input Coordinates Type POINTGRID Mandatory INPUT Number of Points The dimensions expressed in number of rows and columns of the equally spaced grid of points at which the sensitivity vector will be calculated to be automatically generated where Input Coordinates Type is POINTGRID Example Number of Points 10 optional parameter Input Coordinates The coordinates in row col or lat lon of the point s at which the sensitivity vector will be calculated where Input Coordinates Type is ROWCOL or LATLON Example Input Coordinates 45 0 15 0 optional parameter 97 BEST User Manual v4 0 2 10 Statistical This chapter documents the following tools 1 Global Statistic Calculates a range of statistical parameters mean standard deviation coefficient of variation equivalent number of looks for an image or region of interest within an ima
75. ant step towards producing a meaningful backscattering coefficient image The speckle filter tool operates on real intensity images in the internal SAR Toolbox format If the input data is from a PRI image this will initially be in amplitude form and will therefore first need to be converted to an intensity image i e using the Amplitude to Power function The various parameter values shown in the following Speckle Filter Summary Table are those recommended for ERS ESA PRI products Or if the data is from a SLC image the data will first need to be converted to a real form i e Modulus extraction followed by a conversion to intensity i e the Amplitude to Power function Of course if required the output from the Speckle Filter function may be converted from intensity to amplitude form by using the Power to Amplitude function The Speckle Filter makes use of a range of different masks that are applied in a moving window that covers the input image For each position of the window the masks are used to determine the structure of the dominate feature within the window Once this structure has been discovered the filter may either preserve the pixel value at the centre of the window replace it with the mean of the window values in the case for homogeneous regions or use the GAMMA GAMMA MAP filter to evaluate the centre pixel value Further details about the masks used in the Speckle Filter algorithms are given after the Speckle F
76. arameter Input Media Path The path of the media unit fora PC CDROM use Input Media Path D data ASAR DS1 ASA_IMP_1P 320 N1 fora Unix EXABYTE device use Input Media Path dev rst1 for a Unix CDROM device use the entire path to the selected scene ERS SAR product CDROMs can have multiple scenes on them Input Media Path cdcom SCENE1 mandatory INPUT BEST extension data product AOI specification see Appendix 4 optional parameter default is entire input image Header Analysis File The internal format file containing all the decoded annotations obtained during the HEADER ANALYSIS operation on the same product with the associated extension HAN Example Header Analysis File header_IMP HAN mandatory INPUT BEST extension HAN Output Image The name to be given to the internal format image that will contain the selected area of interest at full resolution an extension XT is automatically added by the system where the indicates that the output image retains the same format as the input image Example Output Image full_IMP mandatory OUTPUT BEST extension XT where indicates that the output image retains the same format as the input image 42 BEST User Manual v4 0 2 Portion Extraction Description The PORTION EXTRACTION function extracts a full resolution sub scene from an image already ingested into the Toolbox file format
77. as an approximate figure of merit for the co registration The GCPs that are not used because they have coherence values falling below the coherence threshold are indicated with a symbol next to the coherence value GCPs that are excluded because they have exceeded the value of the Editing RMS parameter are indicated by a symbol in place of the coherence value The residual file can also provide a useful starting point for selecting GCPs to be used in a Specified GCPs file to refine the co registration Interpolation After the warp function has been computed the next step in the co registration process is the interpolation of the slave image pixels onto the master image grid The interpolating function can be selected using the parameter Interpolation Mode The fastest and least accurate interpolators are the nearest neighbour bilinear and constant shift while the most accurate one is the cubic convolution The most precise is the sinc which uses a configurable kernel size to obtain the interpolated value It is also possible to mix two different types of interpolation one method for the row direction and another for the column direction this facility may be useful depending on the distortions suffered by the SAR images for example for interferometric pairs the distortion in the column direction is often very low compared to the row direction The following interpolators can be used e Nearest Neighbou
78. at or co registered images or real as coherence images from slant range onto a flat ellipsoid surface The following steps are implemented e construction of a regular interpolation axis in ground range by coordinate conversion from row col to x y z e evaluation of a set of ground range to slant range polynomial coefficients having a fixed degree for a fixed number of rows of the slant range image e evaluation of the corresponding ground range values from slant range azimuth using the previously evaluated coefficients e range interpolation of the image data with the cubic convolution interpolator The cubic convolution interpolator uses five interpolations with a four coefficient cubic convolution kernel applied to the sixteen pixels around the position determined by the transformation function The tool makes no adjustment to the data in the azimuth direction Therefore an elongated single look complex image will remain a single look image The purpose of the SLANT TO GROUND RANGE CONVERSION tool is to redistribute the data in range with equal pixel spacing See below for the full sequence of processing necessary in BEST to convert SLC data to a multi looked output image The figures below show quick look images with superimposed latitude longitude grids of an IMS image of Barcelona before and after slant to ground range conversion 91 BEST User Manual v4 0 2 left Quick look of an SLC image over Barcelona 2377 col
79. ave Instrument onboard Envisat and ERS 1 amp 2 respectively BEST has evolved from the ERS SAR Toolbox The Toolbox operates according to user generated parameter files The software is designed with an optional graphical interface that simplifies specification of the required processing parameters for each tool and for Windows versions only sets it running The interface doesn t include a display function However it includes a facility to convert images to TIFF or GeoTIFF format so that they can be read by many commonly available visualisation tools Data may also be exported in the BIL format for ingestion into other image processing software The tools are designed to achieve the following functions Data Import and Quick Look basic tools for extraction of data from standard format ESA SAR products generation of quick look images import of TIFF and GeoTIFF files and generic raster data Data Export output of data to selected common formats generation of RGB composites Data Conversion conversion between different image formats transformation of data by flipping or slant range to ground range re projection calculation of sensitivity vectors Statistical calculation of global or local statistical parameters from real image data computation of the principal components of multiple images Resampling over and under sampling of an image by means of spatial and spectral methods Co registration automatic co registration
80. be dismounted from the unit at the end of the volume processing shall be set to N when a series of repeated extraction operations are planned on the same cassette thus avoiding repeated unit mounting This parameter is ignored i e is assumed Y for multi volume processing Example Dismount Volume N optional parameter default is Y 39 BEST User Manual v4 0 2 Full Resolution Extraction Description The FULL RESOLUTION EXTRACTION function is used to extract a full resolution image portion from a product on tape CD ROM or hard disk The resulting image file will be in the BEST internal format and will contain the image pixels plus the various header fields i e the image ancillary data already obtained with the HEADER ANALYSIS operation The extracted image has the same pixel format as the source data no conversion is applied on the pixel values Hence the output image from the FULL RESOLUTION EXTRACTION tool will be given an extension X7 where the question mark will be replaced by either r i s t f or c depending on the data being read when the operation takes place on ERS SAR RAW products from the source media when the operation takes place on 8 bit data generated by the gain conversion tool when the operation takes place on Precision or Geocoded products from the source media when the operation takes place on Complex products from the source media when the operation takes place on inter
81. complex image 6 Integer to Float Conversion Converts a real image from the integer format to the floating point format 7 Ancillary Data Dump Generates an ASCII listing of the image annotations relating to an image in the Toolbox internal format 8 Image Operation Performs basic algebraic operations sum subtract multiply or divide between two images or between one image and a constant factor It is also possible to calculate the absolute value of a single image 9 Geometric Conversion Converts between row column and latitude longitude coordinates for points specified in any given image Also calculates the satellite s position and angles of incidence and look for the specified points 10 Slant Range to Ground Range Conversion BEST User Manual v4 0 2 Reprojects images from slant range range spacing proportional to echo delay to ground range range spacing proportional to distance from nadir along a predetermined ellipsoid The tool works on complex data extracted and or co registered SLC products and real data coherence products 11 Flip Image Executes a horizontal or vertical flip operation or both on any internal Toolbox format image 12 Sensitivity Vector Evaluation Calculates the sensitivity vector of an input image point by point Statistical tools 1 Global Statistic Calculates a range of statistical parameters mean standard deviation coefficient of variation equivalent number of looks f
82. ction to 8 character imposed by the need that the system can run on DOS which cannot handle long names The information about the product type the sensor the format the source facility and also the single or multi volume are coded in the following way The FDF name is PTYSFSRC SMV where PTY is the three character product type RAW SLC SLI PRI GEC GTC S is the single digit number representing the sensor id 1 2 F is the single character format id C M SRC is the three character source station ITP DEP UKP DEP SIS or a new station SMV which is the extension can be CFS for single volume products CFF for multi volume products first volume CFC for multi volume products center volume s CFL for multi volume products last volume The various sections of the DFD name shall follow the same values used in the Nominal Media Structure File As an example if in the Nominal Media Structure File there is an entry describing a PRI product coming from a certain ACM station in a format CEOS acquired by a ERS2 sensor split on 1 volume the corresponding FDF file shall be named PRIZCACM CES If was split on two volumes the two FDF shall be named PRIZCACM CFF and PRI2CACM CEL while if was split on three volumes the three FDFs should be PRPCACM CFF PRIZCACM CFC PRIZCACM CEL 62 BEST User Manual v4 0 2 8 Data Export This chapter documents the following tools 1 Export GeoTIFF Converts data from internal format to a GeoTIFF
83. d These numbers should be less than 1 see the second example INI file below The kernel can be selected for one of a set of predefined kernels or can be defined by the user A list of the pre defined kernels is given here after the example INI file The kernel file is a simple ASCII file containing rows of coefficients separated by spaces with each row terminated with a newline return character There are two modes in which the kernel files can be used 2D One method allows 2 dimensional filters to be defined directly In this case an example of an ASCII file for a 3x3 averaging filter would be 0 1111 0 1111 0 1111 0 1111 0 1111 0 1111 0 1111 0 1111 0 1111 This particular example is contained in the pre defined file usam33 ker 2 x 1D The other method makes use of two 1 dimensional filters to effectively synthesise a 2 dimensional filter This method involving two 1 dimensional filters can be much faster than the direct use of a 2 dimensional filter For example for a 11 rows by 11 columns filter this filtering can be five times faster than a conventional 2 dimensional filtering The two 1 dimensional filters that would produce the equivalent filter to the 3x3 averaging filter shown above would be defined by the following ASCII file 0 3333 0 3333 0 3333 0 3333 0 3333 0 3333 The SAR Toolbox system automatically discovers the correct way to interpret the kernel depending on the layout of the ASCII file As anothe
84. d contains a number of rows this number is chosen to obtain strips of a given size like 8 Kbytes 16 Kbytes and so on The location of the strips is stored in the same indexed way as for the image parameters In this way the image can be easily accessed in subsections and moreover when the compression is applied a strip can be efficiently treated by the compression SW annotations section original image strip 100 TIFF file The image section is kept in the TIFF as a sequence of strips The BTIFF Blocked TIFF is an evolution of this format and has the following characteristics the image is kept on file as tiles instead of strips to improve the image access efficiency independently of the access direction and the position of the sub image accessed annotations section original image BTIFF file The BTIFF Blocked TIFF The handling library does all the job and the user does not have to worry about this structure he can read an image portion in the same way he reads an entire RASTER file Like TIFF the image and the parameters are kept in the same file and in a non positional format i e an index 183 BEST User Manual v4 0 2 table is used If the format or the number of the parameters is changed there is always a backward compatibility and moreover the handling library does not have to be changed in this way a dynamic format can be handled Because the BTIFF is a particular subset of the TIFF the
85. datory INPUT internal format BEST extension f i Example 22s Input Image data PAf where the indicates it or is not important which Input Image data APf module created the files as long as the data type is correct AOI specification ectangular or polygonal AOI specifications optional parameter if not are permitted in row col or lat lon system present the entire input see Appendix 4 for polygonal AOI the image is assumed surrounding rectangular AOI is used the name of the output image in dB units an mandatory OUTPUT extension DBf is automatically added by BEST extension DBf the system Example Output Image data_db 78 BEST User Manual v4 0 2 Complex to Amplitude Conversion Description The complex to amplitude function works on complex images extracting the modulus generating a floating point image containing hence amplitude data The associated output image annotations which define the pixel type are set to amplitude so that those tools which need amplitude data as input data can first execute a check The only AOI which is permitted is the rectangular AOI with corners expressed in row col system Example INI file COMPLEX TO AMPLITUDE Input Dir Output Dir Input Image slc_data XTt Output Image modul_data Complex to Amplitude Summary Table Parameter Description Comment Example the name of the complex image in internal mandatory INPUT fo
86. dia File Skip 2 Data Type 2I File Header Bytes 16012 Line Header Bytes 12 Image Record Length 16012 Number of Rows 500 Number of Columns 500 Swap Bytes N Output Image imported_img Parameter Summary Raster Image Import Input Media Type The type of media on which the raster image is held chosen between disk hard disk tape Exabyte 52 BEST User Manual v4 0 2 cdrom Example Input Media Type disk optional parameter default is disk Input Image When Input Media Type is set to disk or cdrom this parameter gives the name of a 2I or complex 2I image in RASTER format when Input Media Type is set to tape it gives the device name of the tape unit for an image held on the hard disk use Input Image external_img dat for an image held on an Exabyte tape use Input Image dev rst1 mandatory INPUT BEST extension data product Data Type The type of RASTER data to be imported 2P 16 bit real image Complex 21 complex image 16 bits 16 bits Example Data Type Complex 2I mandatory parameter Media File Skip The number of files that precede the image data file to be imported these files will be skipped This parameter is not used when Input Media Type is set to disk or cdrom Example Media File Skip 2 optional parameter default is 0 File Header Bytes The n
87. dicates it is not important which module created the files as long as the data type is correct AOI specification see Appendix 4 optional parameter default is entire input image Class Min A floating point number specifying the second class of the histogram image pixels having a value lower or equal to this shall all contribute to the first histogram bin Example Class Min 100 0 mandatory parameter Class Max A floating point number specifying the penultimate class of the histogram image pixels having a value greater or equal to this shall all contribute to the last histogram bin Example Class Max 900 0 mandatory parameter Classes Number 99 BEST User Manual v4 0 2 An integer specifying the number of classes in the histogram minus 2 the histo gram shall contain two class more than this number the first for all the pixels having a value below Class Min and the last for all the pixels having a value greater than Class Max Example Classes Number 8 mandatory parameter Output File The name of the output ASCII file containing the global statistical data the extension tx is automatically added by the system Example output File glostat mandatory OUTPUT BEST extension txt 100 BEST User Manual v4 0 2 Local Statistic Description The LOCAL STATISTIC function computes a statistical parameter within a usually small window kernel that is allowed to move across an image
88. ding to SBT below UTC_SBT_TIME 22 JAN 2005 UTC 09 41 31 323738 73 Satellite Binary Time 1939849984 satellite_bin_time_code 32bit integer time of satellit e clock Zero if not used 74 dummy 75 Clock Step Size CLOCK_STEP 3906249800 lt ps psec expressed in picoseconds If n gt ot used is set to all zeroes 77 UTC time of the occurrence of the Leap S LEAP_UT 17 OCT 2001 00 UTC E All spaces if not used econd 00 00 000000 78 Leap Second Sign 001 if positive 001 if nega tive 000 if not used 79 Leap second error LEAP_ERR 0 if leap second occurs rwise 0 if not used 0 81 Product Error PRODUCT_ERR 1 1 if there are errors user s hould check SPH or Summary Qua lity ADS for details BEST User Manual v4 0 2 82 Total Size of Product TOT_SIZE 000000000005571 bytes 38358 lt bytes gt Record name Specific Product Header Head Record Pos Esa field name Value Units Tag Remark 1 SPH Descriptor SPH_DESCRIPTOR Image Mod e SLC Image 2 Stripline Continuity Indicator STRIPLINE_CONTINUITY_INDI 0 if the product is a comlete CATOR 000 segment otherwise stripline counter 3 Slice position SLICE_POSITION 001 from 001 to stripline continu ity default is 001 4 Number of slices in this stripline NUM_SLICES gt default if no continuity 001 5 Number of slices in this stripline 001 a num_slices default if no continuity 001 8
89. e first line first pixel corner in the 3 entire image coordinate system line value ile_byte_count 5536 ile_length ile_offset ile_width time_interval_data_point number of seconds between contiguous state vectors s top_left_lat latitude of the first line first pixel corner degree op_left_lon longitude of the first line first 408101 jr 05 J O ioe S S D S S ON Nn lon ie LO Ie Kon N 5 N SIN BR I a a Coo I S U S Neo S on S P 5 169 BEST User Manual v4 0 2 Pp fpixelcorner degreey 0000 top_right_lat latitude of the first line last 52 785542 Cee eee ed top_right_lon longitude of the first line last 16 328794 pe 1 ed vx_sat_1 state vector velocity 1 x 6535 191690 vx_sat_2 state vector velocity 2 x 6283 327860 fe re component component vy_sat_1 state vector velocity 1 y 887 918640 vy_sat_2 state vector velocity 2 y 999 248640 Cee eee eee vy_sat_3 state vector velocity 3 y 1104 391740 eee eee vy_sat_4 state vector velocity 4 y 1202 721190 ee ee ed vy_sat_5 state vector velocity 5 y 1293 646730 A eee vz_sat_1 state vector velocity 1 z 3664 545220 vz_sat_5 state vector velocity 5 z 5135 625370 ea eee E aa 170 BEST User Manual v4 0 2 y scale factor fnternal TTIF flag 0 083333 zsa state vector 1 z component 16138981 080000 zsat2 0 state vector 2 z component _ 5907244 760000 zZsat3 state vector 3 z compon
90. e Description This AMPLITUDE COHERENCE MULTI LAYER COMPOSITE function generates an RGB colour image with three data layers obtained from an interferometric co registered couple The Red channel always contains the coherence of the interferometric couple There are two options for the contents of the Green and Blue channels giving the possibility for two different output colour composite products CAD Red coherence Green average of the modulus backscatter images Blue difference between the modulus backscatter images CMS Red coherence Green modulus backscatter of the master image Blue modulus backscatter of the slave image The layers are rescaled from 16 bit to 8 bit according to the following default methodology e Coherence image a linear scaling between 0 and 0 9 e Modulus backscatter images a logarithmic scaling between 22 dB and 3 5 dB e Modulus backscattering difference image stretched in such a way that the ratio 1 I 10log a is scaled between 1 0 and 6 0 where I and J are the intensity of the 2nd and lst co registered images respectively The user may alter the methodology by setting parameters in the ini file Alternatively an external look up table may be applied afterwards as an 8 bit to 8 bit conversion 8 bits per layer No AOL is permitted in this function Example INI file AMPLITUDE COHERENCE MULTI LAYER COMPOSITE Input Dir Output Dir Coherence Ima
91. e generation some radiometric corrections previously applied to the input image have to be removed Therefore certain related parameters used during the backscattering image generation to apply the radiometric correction are required as input It is important that these parameters are unchanged between the ADC compensation image generation and the backscattering image generation As an example if a user wants to specify a customised calibration constant during the backscattering image generation the same value must be specified here The ADC CORRECTION image generation tool uses as input an ADC lookup table in internal format Nominal files for ERS1 and ERS2 are provided with the BEST software release located in the cfg directory although others can be created if required using the SUPPORT DATA INGESTION tool The reference replica power values used in linear scale are 205229 0 for ERS 1 156000 0 for ERS 2 The reference chirp average density values used are 267200 for ERS 1 201060 for ERS 2 The ADC correction image must be evaluated on the same power image or the image from which a portion has been extracted that will be input to the BACKSCATTERING IMAGE GENERATION tool No Area of Interest AOI parameters can be used with the ADC CORRECTION tool but it can work on image portions Example INI file ADC COMPENSATION GENERATION Input Dir C BEST_out Output Dir C BEST_out Input
92. e of a file in the internal SAR Toolbox format Ancillary Data Dump Summary Table Example Input Image the input image mandatory INPUT BEST extension i f Input Image cfvr LSf Pe 22s IR r where the indicates it is not important which module created the files as long as the data type is correct the name of the ASCII file containing the mandatory OUTPUT annotation listing an extension txt is IBEST extension txt added by the system Example Output File dump 81 BEST User Manual v4 0 2 A sample of a file obtained as output from this function is shown in Appendix 3 together with a table to explain the set of the annotations that are maintained by the various STB tools 82 BEST User Manual v4 0 2 Image Operation Description The Image Operation function allows a set of basic algebraic operations to be performed between two images or between one image and a constant factor The basic operations are sum subtract multiply and divide It is also possible to calculate the absolute value of one image Some example INI files are shown here The following is used for summing two input images IMAGE OPERATION Input Images imagein1 imagein2 Operation Type SUM Output Image imageout This INI file makes it possible to multiply one image with a constant IMAGE OPERATION Input Images imagein Operation Type MUL Output Image imageout Constant Factor
93. e properly fitted by a polynomial warping function This is achieved by making an initial generation of the warp function using all of the GCPs and then excluding the worst GCPs i e those which generate the highest residuals In this way only a set of GCPs which are compatible with the polynomial warp function are selected This operation is controlled by the parameter Editing RMS If the residual for a particular GCP is greater than the defined threshold it will be discarded Specified GCPs In some cases it can be useful for the user to select GCPs on the master image manually This is possible by providing a text file defined by the parameter GCPs File Name containing the GCP coordinates from the master image in the row col coordinate system Obviously there is no need to specify the slave positions of the GCPs as these are computed by the system This option is useful for registering images that contain large regions of low coherence e g an image of a coastal area If the GCPs are not specified directly then they will be uniformly distributed in the image and it may be the case that only a few of them are placed in areas of sufficient coherence In contrast by using the GCP file it is possible to avoid this behavior and concentrate them all in coherent regions Clearly the disadvantage of the Specified GCP method is that it is necessary for the user to do some extra work to obtain the full resolution coordinates of the
94. e recognizing the recognizing egions under a very strict criterion For example Scatter Threshold 0 57 the name of the output image in internal mandatory OUTPUT format containing the speckle filtered BEST extension SFf intensity image an extension SFf is automatically added by the system Output Image specklefiltered_img the filename containing filtering masks mandatory parameter for defined by the user the user masks are the filtering with user used instead of the standard when this masks parameter is present Mask File usermask ker Number of Look the number of looks of the input image optional parameter for when this parameter is absent from the images directly coming INI file then the value stored in the from the extraction tool image annotations is used due to the mandatory parameter for change of the image statistics after a image input images which have filtering operation the output image has been previously filtered this value set to O in the annotations thus 138 BEST User Manual v4 0 2 equiring the user to set a right value e g obtained from measures on the filtered image For example for PRI images Number of Look 3 0 the value of the threshold for the ratio optional parameter for detector applied on the edge regions of user standard masks masks this value should be computed mandatory parameter for sing the relation showed in Speckle Filter juser masks hapter of the document fo
95. e reference image The output is a text file indicating the reference image whose ancillary data was used and a list of the original coordinates requested for conversion with their computed equivalents An Out Of Image flag is added to each case where the requested input coordinates in row column or latitude longitude are outside the limits of the reference image Clearly no AOI can be specified in this operation Reasonable checks are executed for verifying the compatibility of Input Coordinates Type and Output Coordinates Type parameter values Also a warning is generated when the Input Coordinates Type parameter value is ROWCOL or LATLON and the number of Input Coordinate parameter values is odd i e not a complete list of coordinate pairs If just one value is supplied the Geometric Conversion task stops and reports an error Otherwise the last value is ignored Example INI files Below are some sample ini files and their results for selected conversions To convert image row to satellite position In this case the tool is used to compute the position of the satellite expressed in the Earth centred X Y Z system of the orbital state vectors at a series of points during the acquisition specified by image row numbers Note that for demonstration purposes two of the specified rows lie outside the reference image under consideration i e rows 100 and 1999
96. eg bottom_right_lat the last line BEST User Manual v4 0 2 45 LAST_FAR_LONG TAG LAST_FAR_LON 46 East geodetic longitude of the last samp 0004781699 10 6 deg bottom_right_lon le of the last line 53 Ascending or descending orbit designator PASS DESCENDING ASCENDING DESCENDING or FULL ORBIT 55 Detected or complex sample type designat COMPLEX envisat_sampletype or COMPLEX Compression algorithm used on echo data on board the satellite 79 Azimuth sample spacing in time Line Tim LINE_TIME_INTERVAL 6 051 seconds au gt e Interval 74631E 04 lt s gt 81 Number of samples per output line 05175 image_width includes zero filled samples for complex images 1 sample i s a I Q pair 162 BEST User Manual v4 0 2 Appendix 2 Example of a Media Analysis output file An example of the ASCII Media Content Report MCR file is shown here The media analysis file is divided into two sections In the first a list of recognised products is given with the three best choices the most likely first In the second section the media structure is shown detailing the number of volumes files and records and their size in bytes Number of Volume s 1 Product Type PRI Sensor Id ERS2 Data Format CEOS Source Id DEP Number of Volume s 1 Product Type PRI Sensor Id ERS1 Data Format CEOS Source Id ESP Nu
97. el 2 If a SAR product does not follow the foreseen CEOS structure if it has come from an exotic PAF Station or if it is damaged media analysis will help the user to understand its condition and may provide the necessary information to customise a FDF file and thus read the data The product recognition operation relies on the correlation of the file structure of the media to a predefined model In case of discrepancies there is a risk of product misrecognition To make use of this function it is necessary to read the output ASCII MCR file and evaluate whether the product under consideration is damaged to a degree that makes it un readable or whether the unexpected format encountered can be incorporated within the Toolbox framework by the creation of a new FDF file Note An example of an output ASCII MCR file is shown in Appendix 2 Typical Processing Chain MEDIA ANALYSIS gt HEADER ANALYSIS gt QUICK LOOK Example INI file MEDIA ANALYSIS Input Media Path dev rst1 Number Of Volumes 1 Output Dir Output MCR File mcr Header Analysis File header_IMP Dismount Volume N Parameter Summary Media Analysis Input Media Path The path of the Exabyte unit Example Input Media Path dev rst1 mandatory INPUT BEST extension not applicable SAR data 33 BEST User Manual v4 0 2 Number Of Volumes The number of Exabyte cassettes on which the entire product is held usually 1 Example Numb
98. ensible value is 0 4 For real images the fine registration step involves a further maximisation of the cross correlation function The fine registration step makes use of a two dimensional downhill simplex algorithm This algorithm is used to search for a maximum in the coherence or cross correlation for real images The algorithm uses two possible stopping criteria which are defined by parameters that can be adjusted by the user The first stop criterion is set by the parameter Coherence Func Tolerance When the change in the coherence produced after a given cycle of the algorithm is below this tolerance the search stops The second stop criterion is set by the parameter Coherence Value Tolerance When the shifts in units of pixels made on the slave cell are below this tolerance the search stops For real data the size of the fine registration cells is defined by the parameter Fine Reg Window Sizes In general the larger the cell window size is the longer the program running time will be For complex data the size of the square window in which the coherence is calculated within the GCP cells is determined by the parameter Coherence Window Size Small values of this parameter can lead to high noise levels in the coherence calculation A value of 7 or 9 is recommended 115 BEST User Manual v4 0 2 Excluding the Worst GCPs It is possible to select only the best GCPs by excluding those that cannot b
99. ension Input Images reall XTs real2 XTs 21 Pr 29s t f c AOI specification see Appendix 4 optional parameter if not present the entire input 85 Constant Factor BEST User Manual v4 0 2 image is assumed the type of operation selected between mandatory parameter Operation Type MUL a floating number to be used as constant in optional parameter needed the selected operation except for ABS if only one input image is given and the operation type is not ABS the name of the output file containing the mandatory OUTPUT esulting image an extension OPf or BEST extension OPc is automatically added by the system OPf or OPc Example Output Image float_img 86 BEST User Manual v4 0 2 Geometric Conversion Description The GEOMETRIC CONVERSION tool computes equivalent image coordinates in a selection of imaging geometry reference conventions for specified points in an image The tool is capable of converting e from row column pairs to latitude longitude pairs e from latitude longitude pairs to row column pairs e from row column pairs to incidence angle look angle pairs only for ERS products except GEC and GTC e from row to satellite position expressed in the Earth centred XYZ system of the orbital state vectors only for ERS products except GEC and GTC All the transformations are computed using the ancillary data contained in th
100. ent 5652398 400000 zero_dopp_azim_last_time time of the last image line zero_dopp_range_first_time time of the first image pixel 5 564405 ms 171 BEST User Manual v4 0 2 Appendix 4 AOI Specification An AOI specified using coordinates can have the following two shapes a rectangular region a polygonal region range azimuth lt _ range E Polygonal AOI A Polygonal AOI The AOI can be placed in two ways respect the SAR image internal partly external The figure a Rectangular AOI is related to a internal AOI while the following figure AOI partly external to the image shows an AOI placed partly externally to the image 172 BEST User Manual v4 0 2 range SAR image azimuth amp Partly external AOI An AOI partly external to the image The Rectangular AOI can be specified in the following forms Top Left Corner and Bottom Right Corner Top Right Corner and Bottom Left Corner Center and Size range SAR image azimuth amp AOI corners Rectangular AOI specified through Top Left Bottom Right Corners range SAR image azimuth BL f AOI corners 173 BEST User Manual v4 0 2 Rectangular AOI specified through Top Right Bottom Left Corners gt range SAR center image e azimuth azimuth size r range size Rectangular AOI specified through Center Size
101. entation of the image in the output files Quick Look Presentation GEOGRAPHIC Geographic forces the data to be flipped so that North is at the top and East is to the right Number Of Grid Lines 2 2 The number of grid lines to be superimposed on the grid image in vertical and horizontal directions The size of the output image in rows and columns In this case the output will have 800 rows and squared Output I Si 800 0 Tepa Be pixels the software will compute and return in verbose the necessary number of columns Window Sizes 3 3 The size of the window used to average the full resolution image to obtain the quick look image Grid Type LATLON The grid image will be annotated with lines of equal latitude and longitude Grid Drawing Mode transparent The labels on the grid image will not obscure the underlying image Dismount Volume N This indicates that the volume drive would not be Full Resolution Extraction dismounted after the operation had finished The FULL RESOLUTION EXTRACTION tool reads data from the original product into the BEST internal format It is a prerequisite for all subsequent processing The user may opt to extract an entire scene or just a portion of it The ASCII ini file generated to run the tool may look something like this FULL RESOLUTION Input Dir C BEST_out Output Dir C BEST_out Input Media Path Input Media Type
102. er 52 75 6 35 Coordinate System ROWCOL Top Right Corner 300 200 Bottom Left Corner 100 500 Coordinate System LATLON Top Left Corner 52 78 6 30 Bottom Right Corner 52 75 6 35 Centre 200 300 Size Unit ROWCOL Size 100 150 Centre 50 50 Size Unit KM Size 1 5 2 0 Coordinate System LATLON Centre 52 460 5 519 Size Unit ROWCOL Size 100 150 Coordinate System LATLON Centre 52 460 5 519 Size Unit KM Size 1 5 2 0 Coordinate System ROWCOL Number of Vertex 4 Ver tex 100 250 250 100 400 250 250 400 Coordinate System LATLON Number of Vertex 4 Vertex 52 78 6 41 52 79 6 34 52 76 6 32 52 75 6 39 BEST User Manual v4 0 2 Coor dinate System statement is not present coordinates expressed in degree units the first coordinate is for lat the second for lon the coordinate system statement must be present the first coordinate is for row the second for column the row col coordinate system is assumed by default if the Coor dinate System statement is not present coordinates expressed in degree units the first coordinate is for lat the second for lon the coordinate system statement must be present the first coordinate is for row the second for col the first size is for row the second for col the first size is for km in row direction1 the second size is for km in col direction the vertices are in the form V lrow V 1col V2row V2col V nrow Vncol the row col coordinate system is a
103. er Of Volumes 1 mandatory parameter Output MCR File The name of the file which will contain the media content report an extension txt is automatically added by the system Example Output MCR File mcr mandatory OUTPUT BEST extension txt 34 BEST User Manual v4 0 2 Quick Look Generation Description The QUICK LOOK GENERATION function is used to generate a reduced resolution standard TIFF format version of an image This is done using averaging and sub sampling operations on the full resolution data to enable the user to quickly inspect an image The full resolution data can be accessed directly from tape or CD ROM thus avoiding the creation of large temporary files on the local disk or from any file that has been created in the Toolbox internal format except for integer 8 bit files i e type i and those generated by this QUICK LOOK GENERATION function or the Data Export tools Important When starting from an original product the QUICK LOOK GENERATION function requires the Header Analysis File extension HAN previously generated on the same product which will contain product identifier parameters needed to access the data from the media The size of the output image is user defined The software can optionally compute the length of one axis given the length of the other assuming square pixels In the case of multi looked input data this means maintaining the aspect ratio of the
104. er prefer to install the software to the Program Files directory it may be necessary to use the MS DOS name PROGRA 1 in the path at the Destination Folder page of the InstallShield dialogue Paths containing spaces or with more than 8 characters are not handled by MS DOS on the Windows 98 platform 2 3 After restarting the computer essential for Windows 98 check that the software is correctly installed by typing the command BEsT in an MS DOS window If the software is correctly installed you should see the following message ini xi Microsoft Windows XP Version 5 1 2688 lt C Copyright 1985 2661 Microsoft Corp C gt best BEST Generic Tool ver 4 8 2 File ini not found The Visual Basic HMI is launched by double clicking the BEST icon on the desktop linked to c best bin BESTW exe BEST User Manual v4 0 2 Linux 1 4a 4b 4c It is first necessary to determine which shell will be used on the target system The standard shell for Linux is the Bourne Again shell but the C shell tcsh and the Korn shell are also possibilities At the prompt in a newly created shell type echo SHELL The output indicates the current shell as follows bin csh the login shell is the C shell or tesh bin tesh the login shell is tesh bin sh gt the login shell is the Bourne shell bin bash the login shell is the Bourne Again shell bin ksh gt the login shell is the Korn
105. es spectra Overlap Selection The common zone in the master and slave images that shall be co registered and written to the output files can be defined in a variety of ways selected using the parameter Overlapping Mode e AOL in which the common portion to be processed is specified by the user Any kind of AOI can be used except the example image mode e Minimum Overlap where the common portion to be processed contains the pixels which are present both in the master and in all the slaves this portion corresponds to the common overlap zone between all the images of the input stack e Maximum Overlap where the full extents of all images are processed pixels are present in at least one image the portion corresponds to the maximum extents of the input stack e Master Overlap where the common portion to be processed contains the pixels present in the master image Note that the overlapping area among the images is estimated at the beginning of the processing chain If it is found to be less then the threshold established in the parameter Overlapping Aol Threshold the program ends with an error P EEREPEREEPEEREERREE P E EEEEPEEEPEEREEREEH a EEREREREERSRERBEREN a EERERERESEERERBEREN abet 3 SEE BE BER SER SERERE Benes Bese 4 Pettit Se ERS SESE SESS Ps Score Renee oe Ree oe R E PE EEP EEP SSC CEE PEEN SEES ESS RER REESE RERERERERS RER RR RERERERERS BERRRERER RER EREEEUPEEDPEETER
106. escribes the logical and physical format of the field which it refers to Note that a file section can group several record sections into blocks using the repeat construct when iterations on that set of records are required Field Sections A field section describes how the related field has been filled when de formatting or must be filled when formatting Each field section is composed by the following sub sections Field number indicates the field ordinal number within the record Field offset indicates the starting bytes as an offset from the beginning of the record Internal format flag it is a flag the value can be Y or N that specifies if the field has to be considered a product annotation that means characteristic of the product independently from its format or a format annotation that means characteristic of the product format but not of the product data itself Note that all the product annotations are also inserted into the product file in internal format whereas the format annotations are not included into the product as they can be obtained from the header listing file if necessary Align type can be L R or C indicating if the field value has to be respectively left aligned right aligned or centered aligned respect to the field size As a default numeric fields are generally left aligned whereas text fields are right aligned Field format it describes the formatting convention to be used t
107. f when inserting it into the internal format image The format specifications characteristics of annotations are meaningful to properly compute the size of buffers to be used when reading the product format These information are all included into the FDF file It is allowed the use of variables Two kinds of variables are available internal variables named global variables external variables The first ones are useful for two main purposes to store some values that could be necessary later in future steps that could come when that values are no more available if they are not stored in temporary and globally accessible variables to access values that are automatically maintained and updated by the de formatter itself such as the current date the number of bytes read from the current record the current number of processed records and so on There exist a set of pre defined global variables the programmer can use In addition he can define his own set of global variables and can assign values to them If useful they can also be initialized for this purpose an apposite optional section of the FDF named declaration section is provided 58 BEST User Manual v4 0 2 The following sections can be found into a description file Declaration Section It contains the declaration and the initialization of the global variables that must have an initial value This section should at least contain the variables which describes the var
108. for ERS would be z 0 01 0 3 0 9 Hence D x y 0 01 dy 0 3 de 0 9 dy In this case D x y is principally a measure of the vertical component of a real displacement with a contribution from any movement in the East West Sensitivity to movement in the North South direction is negligible The sensitivity vector is determined by the incidence angle and orbital inclination of a radar system By increasing the incidence angle possible using image swaths 3 to 7 of Envisat ASAR the sensitivity to the East West component of a ground displacement increases whilst the sensitivity to the vertical component decreases The following example shows the format of an output 1xt file for a point defined by lat lon For each input row col or lat lon point the local east north and vertical components of the sensitivity vector are reported in metres BEST ESA Telespazio SENSITIVITY File Lat Lon Sn m Se m Sv m 0 36 50000000 114 59999847 0 347267029 0 347259363 0 001754421 Example INI file SENSITIVITY EVALUATION 96 BEST User Manual v4 0 2 Input Dir G Output Dir G Input Image img XTs Output File sns_vect Input Coordinates Type POINTGRID Number of Points 10 Parameter Summary Sensitivity Evaluation Input Image The name of the internal format input image Example Input Image img XTs M
109. for PC and because the handling library is exactly the same the TTIFF has been selected as the internal format of STB This will permit the direct ingestion of the STB images into display SW which accept as input the TTIFF format The unique limitation of TTIFF compared to BTIFF is the loss of the possibility to store the tiles vertically which is of some utility only in the case of a vertical image elaboration e g like the azimuth compression in SAR processing but is surpassed by the advantage of the direct ingestion of the STB internal images in the image processing SW without any conversion to standard TIFF However to permit the visualization of the STB images under old SW which does not have the TTIFF ingestion capability the STB will allow the generation of non tiled standard TIFF images with some little modifications both to the tags concerning the tile dimensions and a re formatting of the image in order to transform tiles into strips In case of complex and other non 8 bit images a transform to a single 8bit image is performed IDL is capable of reading TIFF images using the TIFF_READ command having the following syntax Result TIFF_READ File R G BJ where File is the file name of the image R G and B are optional vectors used to store the look up table of a Palette color image and Result is a two dimensional matrix containing the image pixels If the TIFF image is a RGB true color one Result will be a three dimensional mat
110. for visualisation Therefore the tool is often applied prior to exporting to the TIFF format In a SAR image 99 of the image data may have pixel values between 0 and 1000 However the maximum value of the image may be as great as 30 000 If the conversion from 16 bit to 8 bit is done with a simple scaling the resultant image will appear all black except for a very few isolated pixels having very high values The GAIN CONVERSION tool has facilities to allow the conversion to be made in such a way that the image can be more sensibly visualised The only Area of Interest that is permitted is the rectangular AOI with corners expressed in the row col system The gain conversion module allows the following three modes of operation The mode is selected by a parameter specified in the ini file i Fixed Gain Conversion In this mode all of the input image pixel values are divided by a fixed gain value selected by the user If the pixel values after the division exceed 255 they are saturated at 255 In this way a very simple radiometric stretch scheme can be implemented The limitation of this method is that the optimum scaling will be dependent on the kind of scene contained in the SAR product The gain constant will therefore need to be chosen carefully or by using a process of trial and error ii Variable Gain Conversion In this mode a linear stretch is performed on those pixels with values that fall between two upper and lower radiomet
111. freq_linear 966150 437500 cross_dopp_freq_quad 1370826624 000000 day_data_point 22 ellipsoid_semimajor_axis 6378 137207 ellipsoid_semiminor_axis 6356 752441 incid_angle_centre_range 0 000000 line_spacing 4 043083 map_proj_descr Slant range month_data_point 1 nom_nb_looks_azim 1 000000 nom_nb_looks_range 1 000000 normalisation_ref_range 800 000000 orbit_num 15149 pixel_spacing 7 803975 processor_range_compression NOMINAL radar_wavelen 0 056236 replica_power 2 833618 sampling_rate 19 207680 scene_ref_num ORBIT 15149 second_of_day 35756 515625 sensor_plat_mission_id time_interval_data_point 4 068438 164 top_left_la top_left_lo top_right_l top_right_l year_data_p zero_dopp_azim_first_time t n at on oint 43 932 6 3460 44 132 5 0604 zero_dopp_azim_last_time BEST User Manual v4 0 2 220 62 128 72 2005 22 JAN 2005 09 55 56 517 22 JAN 2005 09 56 12 790 zero_dopp_range_first_time 3 929571 int_top_left_east 0 000000 int_top_left_north 0 000000 int_top_right_north 0 000000 int_top_right_east 0 000000 int_bottom_left_east 0 000000 int_bottom_left_north 0 000000 int_bottom_right_north 0 000000 int_bottom_right_east 0 000000 input_columns_nb
112. ge cohe CHf Co registred Images slc_master CRc slc_slave CRc Output Image mlayer Multi layer Mode Flag CAD Coherence Upper Threshold 0 75 Image Lower Threshold 18 Image Upper Threshold 2 5 DiffImage Lower Threshold DiffImage Upper Threshold ray GE Br Fi 2 3 Parameter Summary Amplitude Coherence Multi layer Composite Coherence Image 132 BEST User Manual v4 0 2 The name of the input coherence image Example Coherence Image cohe CHf mandatory INPUT BEST extension CHf Co registred Images The name of the input interferometric co registered image couple Example Co registred Images slc_master CRc slc_slave CRc mandatory INPUT BEST extension CRc or CRf Output Image The name of the output true colour RGB multi layer image in internal format Example Output Image mlayer mandatory OUTPUT BEST extension tif Multi layer Mode Flag The type of output colour composite image to generate CAD CMS Example Multi layer Mode Flag CAD mandatory parameter Coherence Upper Threshold The upper limit for the linear scaling of the coherence real image stretching from 16 bit to 8 bit Example Coherence Upper Threshold 0 75 optional parameter default is 0 9 Image Lower Threshold The lower limit in dB for logarithmic scaling of the average modulus backscatter compu
113. ge tl_priimage XTs f where the indicates it is not important which module created the files as long as the data type is correct AOI specification only the Rectangular AOI specifications are joptional parameter if not permitted see Appendix 4 present the entire input image is assumed the name of the ASCII file which contains mandatory parameter the coefficients of the filter used to subsam ple the input image the file names of the preset filters are shown in the previous table Filter File Name usam55 ker the size of the output image shall be lower This parameter is an alter than the input image size this number per native to Output Image mits to control the undersampling factor Ratio Output Image Size 20 15 Output Image Ratio The row col ratios to determine the size of This parameter is an alter the output file These numbers should be native to Output Image between 0 0 and 1 0 Size Output Image Ratio 0 7 0 5 the name of the output image in internal mandatory OUTPUT format containing the undersampled image BEST extension UNf an extension UNP is automatically added by the system Example Output Image under sam 112 BEST User Manual v4 0 2 12 Co registration and Coherence Generation This chapter documents the following tools 1 Co registration Registers one or more images to another using up to three separate processes to achieve a precise fit Images can be real or complex
114. ge Also generates a histogram of the pixel values 2 Local Statistic Generates output images showing a range of statistical parameters mean standard deviation coefficient of variation equivalent number of looks computed from an image using a moving window of selectable size 3 Principal Components Analysis Generates the first and second principal components from a pair of input images 98 BEST User Manual v4 0 2 Global Statistic Description The GLOBAL STATISTIC function computes some statistical parameters for an image or area of interest AOD within an image The statistical parameters are the standard deviation coefficient of variation equivalent number of looks mean value image maximum image minimum and a histogram of the pixel values These values are global i e one unique value of a certain statistical parameter is given for the entire AOI The AOI can be specified in any way except the example image mode Example INI file GLOBAL STATISTIC Input Dir C BEST_out Output Dir C BEST_out Input Image tl_priimage XTs Top Left Corner 100 100 Bottom Right Corner 700 700 Class Min 100 0 Class Max 900 0 Classes Number 8 Output File glostat Parameter Summary Global Statistic Input Image The name of the input real image in internal format Example Input Image tl_priimage XTs mandatory INPUT BEST extension s 1 2 f where in
115. hat any BEST module could have produced this file AOI specification see Appendix 4 for polygonal AOI the surrounding rectangular AOI is used optional parameter default is entire input image Output Image The name of the output image containing amplitude data the extension PAf is automatically added by the system Example Output Image ampl_data mandatory OUTPUT BEST extension PAf 76 BEST User Manual v4 0 2 Amplitude to Power Conversion Description The AMPLITUDE TO POWER CONVERSION tool computes the square of the input image pixel values thus generating a floating point image representing the power of an amplitude image In the output image annotation the pixel type is set to power so that those tools that need power data as input data can first execute a check The only AOI permitted is the rectangular AOI with corners expressed in row col The tool works both with real images and complex data in the latter case the square modulus is computed as output This feature can replace the use of the pipeline between the modulus extraction COMPLEX TO AMPLITUDE CONVERSION and the AMPLITUDE TO POWER CONVERSION tools necessary for most complex data processing see below Typical Processing Chain HEADER ANALYSIS FULL EXTRACTION gt AMPLITUDE TO POWER CONVERSION Example INI file AMPLITUDE TO POWER Input Dir C BEST_out Output Dir C BEST_out Input Image ampl
116. he ADC saturation correction is required an ADC correction image shall also be provided as input This correction image should be previously generated using the ADC CORRECTION image generation tool described on the following page The BACKSCATTERING IMAGE GENERATION tool needs a value for the ADC saturation correction for every pixel in the image so the ADC correction image must be computed using the same image portion used here or a larger dataset from which a subset used here was taken An error message is issued when this condition is not respected Example INI files The following ini file is the simplest example for backscattering image generation from a PRI power image without any correction for the replica power variation or ADC saturation IMAGE BACKSCATTERING Input Dir C BEST_out Output Dir C BEST_out Input Image pri APf Calibration Constant Correction APPLY Output Image Scale DB Output Image pri_s0 144 BEST User Manual v4 0 2 The following ini file is an example of fully compensated backscattering image generation from a PRI power image processed at a PAF that annotates the replica power value in the PRI the antenna pattern and the range spreading loss are already compensated during the SAR processing IMAGE BACKSCATTERING Input Dir C BEST_out Output Dir C BEST_out Input Image pri APf Replica Power Correction
117. he image annotations is used Example Calibration Constant 1000000 0 optional parameter Output Image Scale The scale of the output backscatter image LINEAR R DB Do not use the dB scale if a further step of averaging is foreseen Example Output Image Scale DB optional parameter default is LINEAR Output Image The name of the output image in internal format containing the backscatter data an extension BSf is automatically added by the system Example output Image backscatt mandatory OUTPUT BEST extension BSf 147 BEST User Manual v4 0 2 ADC Compensation ERS Description The ADC CORRECTION image generation tool computes the ADC compensation image that is required by the BACKSCATTERING IMAGE GENERATION tool to correct for the ADC saturation effect This effect present in all ERS images but particularly those from ERS 1 can alter the derived backscattering values on high reflectivity zones The ADC image generation is based on two filters with averaging kernels The first called RMS averaging is used to reduce the computational load The second called smoothing uses a window size dependent on the length of the functions used during the original SAR processing which vary between SLC and PRI products as follows Smoothing window size for PRI products 400 rows 1200 columns Smoothing window size for SLC products 630 rows 1280 columns During the ADC compensation imag
118. he size of the sinc interpolation kernel in units of pixels This value affects the accuracy of the interpolation at the expense of the processing time Example Sinc Width 7 optional parameter default is 7 Cubic Convolution Coefficient A coefficient which modifies the behaviour of the cubic convolution interpolator the IDL cubic interpolation uses a coefficient equal to 1 while ERDAS suggest 0 5 Example Cubic Convolution Coefficient 1 0 optional parameter default is 1 Overlapping Mode The type of overlapping scheme MIN MAX MASTER Example Overlapping Mode MASTER optional parameter default is MASTER Residual File Name The name of the text file which will contain the warp coefficients and the residuals for each GCP Example Residual File Name residual optional OUTPUT default is residual txt Overlapping Aol Threshold This parameter is the minimum allowable common area between the master image and the slaves expressed as a percentage of the master image area The minimum value for which co registration is still considered possible is assumed to be around 30 Example Overlapping AoI Threshold 10 optional parameter default is 30 123 BEST User Manual v4 0 2 Coherence Generation Description The COHERENCE GENERATION tool computes the coherence image between two co registered complex or real SAR products The coherence is generated in a
119. ication ectangular or polygonal AOI specifications optional parameter if not are permitted in row col or lat lon system present the entire input see Appendix 4 for polygonal AOI the image is assumed surrounding rectangular AOI is used the name of the output image containing mandatory OUTPUT floating point data an extension IFf is BEST extension IFf automatically added by the system Example Output Image float_img 80 BEST User Manual v4 0 2 Ancillary Data Dump Description The ancillary data dump creates an ASCII file containing a listing of the image annotations which are stored in the specified internal format image The listing includes the following fields a line progressive index the annotation name the annotation value and is a fast way to check the value of the image annotations The SAR Toolbox system maintains the entire annotation set only for the header file coming from the extraction tools The remaining tools maintain only the annotations needed which are considerably less due to the fact that the most part of the original CEOS or MPHSPH are not used for the SAR Toolbox processing with the exception of the TIFF and the BIL conversion function which cut all the annotations from the output file Example INI file ANCILLARY DATA DUMP Input Dir Output Dir Input Image cfvr LSf Output File dump Note The extension LSf for the Input Image is just one possible exampl
120. ile using XV it is necessary to launch the software first and load the image from the browser rather than typing the command xv quicklook tif BEST data can also be exported using the EXPORT TO BIL tool This converts one or more maximum 10 integer or float images in the Toolbox internal format to a band interleaved by line BIL file i e where consecutive records contain scan lines from each band in turn before moving from one row to the next that can be used in an image viewer capable of ingesting such data e g ERDAS or ER Mapper Using the BIL format makes it possible to maintain the data in the source floating point representation thereby retaining the accuracy of the data ER Mapper ER Mapper includes an import function to load a TIFF image and transform it into its internal format This option can also be activated via the operating system shell with the following command importmany TIFF image file ERMAPPER image file Grey level TIFF image files are transformed into a single band ER Mapper file while both RGB true colour and palette colour images are transformed into three band ER Mapper image files BEST User Manual v4 0 2 5 Installation Windows 98 2000 NT N B Windows 2000 or Windows NT users will need to be logged on as Administrator 1 Double click the executable file and follow the instructions in the dialogue boxes N B The default destination folder is c best Should the Us
121. ilter Summary Table Further characteristics of the speckle filter tool are it uses only the rectangular AOI specification with corners expressed in row col system it uses for the standard masks odd filter sizes ranging from 3 by 3 to 31 by 31 with a corresponding number of directions from 4 to 60 the upper kernel size limitation is only imposed by the automatic computation of the thresholds if these values are inserted from the user a greater kernel can be used used predefined masks evaluating in an automatic way the edge and line thresholds can also apply user defined masks once the edge and line thresholds are specified by the user updates in the output image the following annotations the new values of the coordinates in lat lon of the four corners and of the center point the new entry in the processing history the speckle filtering function is interfaced with ERMAPPER using the filter feature 136 BEST User Manual v4 0 2 Example INI files The following INT file is an example for the speckle filtering of a PRI image portion with standard masks SPECKLE FILTER Input Dir Output Dir Input Image tl_priimage APf Top Left Corner 50 50 Bottom Right Corner 500 500 Window Sizes 11 11 PFA 10 0 Scatter Threshold 0 57 Output Image specklefiltered_img The following file does the same operation with user mask SPECKLE FILTER Input Dir Output Dir
122. image that includes geographic information 2 Export to TIFF Converts 8 bit data from the Toolbox internal format to standard TIFF format as either single channel greyscale or 3 channel colour images 3 Export to BIL Converts one or more up to ten internal Toolbox format images having the same size and data type to one binary image in BIL Band Interleaved by Line format 4 Export to RGB Converts three internal Toolbox format images with the same size to a 24 bit RGB image 63 BEST User Manual v4 0 2 Export GeoTIFF Description The EXPORT GEOTIFF tool is based on the functions of the related handling library The GeoTIFF format is a variation of the TIFF image file format which additionally conveys geographic information No AOL is permitted in this export operation Example INI file GEO TIFF GENERATION Input Dir C BEST_out Output Dir C BEST_out Input Image asar_apm XTs Output Image exp_gtif Delete Input Image N Parameter Summary Export GeoTIFF Input Image The image to be exported to the GeoTIFF format Example Input Image asar_apm XTs mandatory INPUT BEST extension 1 22s 22t 2 f or c where indicates that any BEST module could have produced the file Output Image The name of the output GeoTIFF file containing the image and geographic annotations Example Output Image exp_gtif mandatory OUTPUT B
123. in NODEC byte ordering Kn that means a binary field of length n 1 e a sequence of n bytes with n equal to 1 2 or 4 in DEC byte ordering Image data The image data records are recognized by the condition of a REPEAT statement followed by a single record definition The REPEAT shall use a difference between the two reserved global variables START_LINE and END_LINE These two variables shall appear defined in the FDF and associated with a couple of fields Rn that means image sample with a pixel having 16 bit unsigned integer format in NODEC byte ordering The number n is not used in the subsequent processing If this field starts at a byte position different from 1 the previous bytes are considered as line header and not inserted in the image Vn that means image sample with a pixel having 16 bit unsigned integer format in DEC byte ordering The number n is not used in the subsequent processing If this field starts at a byte position different from 1 the previous bytes are considered as line header and not inserted in the image Cn that means image sample with a pixel having 8 bit signed integer format The number n is not used in the subsequent processing If this field starts at a byte position different from 1 the previous bytes are considered as line header and not inserted in the image Tag name it is the symbolic name of the field the system uses this name to retrieve the associated tag a 16 bits number greate
124. ing user mask are for user masks the edge and line thresholds cannot be computed by the system refer to the Speckle Filter chapter of the document A3 for details and shall be given by the user the mathematical computations are however quite complex and also use empirical formulas in the Speckle Filter chapter of the document A3 some values are given for certain filter sizes and PFA values the various regions e g the line or the edge shall always be centred on the central mask pixel The user masks can be useful if it is required that the speckle filter recognize special image features like the curved line in the following mask edgeline 1 2 344444444 2 344444444 2 344444444 2 334444444 22 3334444 1122 3344 1111222 33 111111122 3 111111112 3 111111112 3 111111112 3 142 BEST User Manual v4 0 2 14 Calibration This chapter documents the following tools For ERS data 1 Backscattering Image Generation Converts a power image into a backscatter image 2 ADC Compensation Corrects a power image for the ADC saturation phenomenon in ERS SAR products prior to BACKSCATTERING IMAGE GENERATION 3 Gamma Image Generation Converts a backscatter image i e output from BACKSCATTERING IMAGE GENERATION into a Gamma image by dividing by the cosine of the incidence angle For ASAR data 4 Backscattering Image Generation Converts a power image into a backscatter image 5 Retro calibration Removes an a
125. ins became a very simple task requiring just the appending of the various elementary INT files in one unique file and their subsequent activation Let us suppose that we need to generate from a SLC image portion already extracted the related square modulus This can be obtained with the data conversion tool first converting the complex input to modulus and then raising it to the square These two operations can be combined in the following unique INT file save it with name powmodulus ini COMPLEX TO AMPLITUDE Input Dir Output Dir Input Image slcimage e5 Output Image modulus AMPLITUDE TO POWER Input Dir Output Dir Input Image modulus v2 Output Image power_modulus executed with the following command stbx powmodulus ini The stbx tools have another important feature When the first section in the composite INT file is GLOBAL SETTING the related parameters have a global meaning and can be used by all the functions invoked in the INT file This section can contain assignments for the following parameters only input directory output directory temporary directory delete input file flag The previous example can then be transformed in GLOBAL SETTING Input Dir Output Dir Temp Dir Delete Input Image Y COMPLEX TO AMPLITUDE Input Image slcimage e5 Output Image modulus AMPLITUDE TO POWER Input Image modulu
126. ional parameter default is N Output Image The name of the file to be written in the Toolbox internal format Example Output Image imported_img mandatory OUTPUT BEST extension RIs for real data RIt for complex data 54 BEST User Manual v4 0 2 New Product Adding This is not really a function in the same sense as the other SAR Toolbox algorithms but instead makes it possible to recognise and decode SAR products that were not previously recognised as standard products The New Product Adding function permits the insertion of new format in the set of those recognized by STB The new format descriptor files shall all be kept in the directory CFG To make possible the decoding of a new product the following operations are required generation of a new section in the file in which all the nominal values of the media structure data are kept generation of the FDF file which contains the detailed format structure following the FDF syntax explained in the next section storing of the FDF file in the configuration directory with a proper naming convention After these operations the system is capable to accept this new product and treat as a standard products In the next paragraphs these operations are described in detail Nominal Media Structure File description As already described in the previous paragraph related to the Media Analysis the value of the following parameters the product format the product t
127. ious files and record sizes of the product now described using as example a CEOS PRI Note that the symbol is part of the variable name and should not be omitted for a CEOS PRI MAX_F_SZ 1 360 the maximum record size for the file 1 use O for variable length records of a number for a specified ecord size MAX_F_SZ 2 the maximum record size for the file 2 note that the second file corresponds to the Leader file which has variable length records nnn maximum record size for the file 3 note that the third file corresponds to the Imagery file which could have variable length records MAX_F_SZ 4 B60 ithe maximum record size for the file 4 F R 1 1 B60 the actual fixed record size of the file 1 record 1 F_R 1 2 B60 the actual fixed record size of the file 1 record 2 F R 1 3 B60 Ihe actual fixed record size of the file 1 record 3 F_R 1 4 B60 ithe actual fixed record size of the file 1 record 4 fee SEE E a length GE nn length Te record size of the file 2 record 3 set to variable length En ei length BE BE length pee ee length D EEE length F _R 4 1 the actual fixed record size of the file 4 record 1 BITS_PER_ SAMPLE 6 the size of each imagepixelsinbits image the size of each image pixels in bits in bits eer 3 ee images and 2 for complex i images OO O a oft ingestion ber of records of the image section pasa Pees ste age cade size in
128. ir C BEST rgb RGB Images imal XTs ima2 XTs ima3 XTs Output Image rgb Parameter Summary Export to RGB RGB Images The names of the three internal format images to be written to the channels of the RGB file They should be entered in the order red channel green channel blue channel Example RGB Images imal XTs ima2 XTs ima3 XTs Mandatory INPUT BEST extension 71 s 2 f where indicates that it is not important which module created the files as long as the data type is correct Output Image The name of the output RGB image The extension tif is automatically added by the system Example output Image rgb Mandatory OUTPUT BEST extension tif 69 BEST User Manual v4 0 2 9 Data Conversion This chapter documents the following tools 1 Gain Conversion Rescales floating point or real 16 bit integer data to 8 bits thereby preparing it for export to formats that can be visualised in basic graphics packages 2 Power to Amplitude Conversion Converts a power image into an amplitude image 3 Amplitude to Power Conversion Converts an amplitude image into a power image 4 Linear to dB Conversion Converts an amplitude or intensity image with a linear scale into an image in decibel dB units 5 Complex to Amplitude Conversion Derives the amplitude modulus from a complex image 6 Integer to Float Conversion Converts a real image from the i
129. kten 106 Undersampling Down Sampling cc eeeesceccesssnceeeessnneeeeesssaeeeeesssaeeesesssaeeeeessaeeees 108 12 Co registration and Coherence Generation usa ken 113 COS SISTT AUT ee baad Nad E aaa co aL a EIEE teas 114 Coherence Generation ernennen sees ele eee RDAS 124 Footprint ROS SET on a Ren 126 Image G o correc UON iseinean rE E EE AERES EES 128 Amplitude Coherence Multi layer Composite sssssseeesseesssssseereeeressssserereeesssssseeerree 132 19 Speekle Filter au ze ee a PER CRS ETRE e aai a s een e ea heer ausi 135 Speck ler sn E EE A A E E ee 136 t4 Calibration een oe na eae A 143 Backscattering Image Generation ERS une 144 ADC Comipensation ERS Jeers an Haager 148 Gamma Image Generation ERS as rk klin 150 Backscattering Image Generation ASAR u a 151 Image Retro calibration ASAR u uu u2use aan dena 153 Rough Range Calibration ASAR ihnen hen 155 Swath Enhancement ASARJ unse eek 156 G APPENDIGES 2 BEE 158 BEST User Manual v4 0 2 A OVERVIEW BEST User Manual v4 0 2 1 Introduction What is BEST The Basic Envisat SAR Toolbox BEST is a collection of executable software tools that has been designed to facilitate the use of ESA SAR data The purpose of the Toolbox is not to duplicate existing commercial packages but to complement them with functions dedicated to the handling of SAR products obtained from ASAR Advanced Synthetic Aperture Radar and AMI Active Microw
130. l and evaluated with respect to the parameter Coarse Reg Tolerance The coarse registration step is performed twice using slightly different cell positions In the first instance each cell is centred on a GCP In the second the cell centre is defined by the position found using the first step If the final transformation positions from these two computations do not agree within the limit set by Coarse Reg Tolerance for a particular GCP it will not be used in the remaining co registration process Therefore the parameter measured in pixel units provides a check on the stability of the cross correlation procedure Fine Registration Step step 3 For complex images the fine registration step is based upon a coherence maximisation routine This operates on a series of cells defined at the GCPs For both real and complex images the fine registration step can be switched on or off using the flag parameter Image Fine Reg It is possible to define a Coherence Threshold parameter when using the fine co registration step GCPs are excluded from the co registration calculation if their coherence levels fall below this threshold It is preferable to exclude these low coherence points from the co registration process because otherwise the calculated translations will essentially be random in areas of very low coherence for example over regions of water The Coherence Threshold parameter should have a value between 0 and 1 A s
131. l Processing Chain HEADER ANALYSIS FULL RESOLUTION gt IMAGE GEO CORRECTION Example INI file IMAGE GEO CORRECTION Input Dir C BEST_out Output Dir C BEST_out Input Image full_IMM XTs Output Image geo_IMM Interpolation Mode SINC Parameter Summary Image Geo correction Input Image The name of the input ASAR Medium Resolution image in internal format Example Input Image full_IMM XTs mandatory INPUT BEST extension s or f where indicates that any BEST module could have produced this file 130 BEST User Manual v4 0 2 Output Image The name to be given to the internal format image which will contain the geo corrected image an extension GR is automatically added by the system Example Output Image geo_IMM mandatory OUTPUT BEST extension GRf AOI specification see Appendix 4 for polygonal AOls the surrounding rectangular AOI is used optional parameter default is entire input image Interpolation Mode The method of interpolation BILINEAR CUBIC CONVOLUTION SINC Note that the cubic convolution does not work very well with complex data It is strongly recommended that a constant shift or sinc interpolator is used for complex data Example Interpolation Mode SINC optional parameter default is CUBIC CONVOLUTION 131 BEST User Manual v4 0 2 Amplitude Coherence Multi layer Composit
132. l or complex image like a SLC product using the FFT and Zero Pad algorithm The algorithm takes into account the value of the Doppler Centroid Frequency when padding the azimuth spectrum The size of the output image can either be determined by specifying this directly in terms of the pixel dimensions e g Output Image Size Or in terms of the row col ratios by which the input image should be multiplied These numbers should be greater than 1 see the second example INI file below Only the rectangular AOI with corners specified in row col system are accepted Example INI files The following ini file is an example for the oversampling for an input SLC image portion IMAGE OVERSAMPLING Input Dir Output Dir Input Image slcimage XTt Output Image oversam Top Left Corner 100 100 Bottom Right Corner 199 299 Output Image Size 200 300 The output from the following INI file would have dimensions 299 100 1 1 5 rows and 399 100 1 1 1 columns IMAGE OVERSAMPLING Input Image priimage XTs Output Image oversam Top Left Corner 100 100 Bottom Right Corner 299 399 Output Image Ratio 1 5 1 1 Oversampling Up Sampling Summary Table Example Input Image the name of the input real or complex image mandatory INPUT in internal format BEST extension i f Example ec 22s It r Input Image slcimage XTs where the indicates it is not important which module crea
133. le header_IMS txt Header Analysis File header IMS HAN Typical HMI settings for r Parameters record file name ini file readin gan parameters ini Quit ASA_IMS_IP product Notes Select the product by means of the Input Media Path and Input Product Image fields note that the Sensor Id must be specified before image products appear as selectable The Sensor Mode field is enabled only for the Envisat ASAR sensor The Alternating Polarization Dataset field is enabled only for ASAR AP products it distinguishes between the Ist and 2nd MDS Product Type PRI Precision products IMP APP MR Medium Resolution products IMM WSM SLC Complex products IMS APS GEC Geocoded products IMG APG 29 BEST User Manual v4 0 2 BRW Browse products IM__BP AP__BP The Number of Volumes field is relevant for import from Exabyte tape only Typical Processing Chain HEADER ANALYSIS gt QUICK LOOK FULL RESOLUTION Example INI file HEADER ANALYSIS Input Media Path D data ASAR DS1 ASA_IMP_1P 320 N1 Input Media Type cdrom Sensor Id ASAR Sensor Mode Image Product Type PRI Data Format ENVISAT Source Id esp Number Of Volumes 1 Output Dir C BEST_out Annotation File header_IMP Header Analysis File header_IMP Dismount Volume N Parameter Summary
134. lt for complex data a further fine registration is achieved by the maximization of the complex coherence between the images for a series of cells defined across the images thereby allowing a further improvement on the cross correlation function This step can be executed only if the coarse registration step 2 has been performed It may be disabled by changing the flag parameter Image Fine Reg Input Images The input images for the co registration can be complex i e SLC or SLCI RAW data is not permitted or real i e PRI GEC or GTC All of the input images must be of the same type i e they must all be complex or all real and have the same projection system all slant range or all ground range projected or all geocoded It is therefore not possible to mix product types although the GEC format can been registered with the GTC format because they are both in the east north projection Before performing the main co registration steps the tool makes a quick check to ensure the images overlap to a significant degree If the area of overlap is less than the user configurable threshold Overlapping Aol Threshold the program ends with an error Ground Control Points The coarse and fine co registration steps operate on rectangular regions within the images defined by a series of ground control points GCPs The generation of the GCPs is controlled by one of two methods Normally the GCPs are defined automatically on a
135. m settings The resulting settings appear in the lower part of the dialogue box Help gt Setup Working Directory To ease the process of selecting input and output files from individual dialogue boxes the default directory may be changed using this function at the beginning of a session The specified 23 BEST User Manual v4 0 2 path selected by browsing in a directory tree is subsequently used as the value for Input Dir and Output Dir but above all the function enables the working files generated during the current processing session to be visible immediately when a dialogue box is opened without first having to navigate to the correct directory This makes file management on a large disk much easier The working directory is not retained between sessions but reverts to the specified PATH instead Exit To close the ASAR Toolbox session click on Exit gt Exit The working directory and parameters changed in any of the dialogue boxes will be reset 24 BEST User Manual v4 0 2 B TOOLS 25 BEST User Manual v4 0 2 7 Data Import and Quick Look This chapter documents the following tools 1 Header Analysis Decodes the product header and stores the information in an internal Toolbox format file necessary for input to the FULL RESOLUTION EXTRACTION and QUICK LOOK GENERATION tools Also writes the header information to an ASCII text file for reference purposes 2 Media Analysis Determines
136. mat containing the backscatter data the extension GAF is automatically added by the system Example Output Image gamma mandatory OUTPUT BEST extension GAf 150 BEST User Manual v4 0 2 Backscattering Image Generation ASAR Description The BACKSCATTERING IMAGE GENERATION tool converts a power image into a backscatter image The following radiometric effects are corrected e incidence angle e absolute calibration constant e antenna pattern e range spreading loss Only the first two need be applied to detected ground range products For slant range complex products the last two must also be compensated This differentiation is automatically performed by the system The output image may have either a linear or dB scale Example INI file IMAGE BACKSCATTERING Input Dir G backscattering power Output Dir G backscattering calib prod power Input Image power_IMS2166 APf Output Image Scale LINEAR Output Image bs_pow_IMP4399 Sensor Id ENVI Parameter Summary Backscattering Image Generation ASAR Input Image The name of the input power image in internal format Example Input Image power_IMS2166 APf mandatory INPUT BEST extensions APf XTf IT GT OV UNf DBf OP SGf SGe FI CR where indicates that it is not important what format the dat
137. mber of Volume s 1 Product Type PRI Sensor Id ERS2 Data Format CEOS Source Id ESP Number of Volume s 1 VOLUME 1 FILE 1 Number of Record s Record Size RECORD 4 360 FILE 2 Number of Record s Record Size RECORD T 720 RECORD 1 1886 RECORD 1 1620 RECORD 1 1046 RECORD 2 12288 FILE 3 Number of Record s Record Size RECORD 8202 16012 FILE 4 Number of Record s Record Size RECORD 1 360 163 BEST User Manual v4 0 2 Appendix 3 Ancillary Data Dump Output and Annotations An example of an ancillary data dump is shown here ANNOTATIONS Image C Data ASAR ASA_IMS XTt image_width 5175 image_length 26892 bits_per_sample VectorialTag 0 16 compression 1 photometric_interpretation 1 sample_per_pixel 2 x_print_resolution 300 000000 y_print_resolution 300 000000 resolution_unit 2 tile_width 128 tile_length 128 tile_offset VectorialTag 0 69232 tile_byte_count VectorialTag 0 65536 sample_format VectorialTag 0 2 disposition x absolute_calib_k 34994 515625 antenna_boresight 0 000000 antenna_elevation_gain_flag 0 bottom_left_lat 42 977173 bottom_left_lon 6 045401 bottom_right_lat 43 176392 bottom_right_lon 4 781658 centre_geodetic_lat 43 563950 centre_geodetic_lon 5 510607 early_zero_fill_record_number 0 late_zero_fill_record_number 0 cross_dopp_freq_const 294 598663 cross_dopp_
138. message is issued Due to the capability of the statistical tool to manage polygonal regions the situation shown in the 177 BEST User Manual v4 0 2 figure what the user was thinking does apply notice that only a polygonal region can have sides not parallel to the range and azimuth axes AOI specification by example image The remaining way to specify the AOI is associated to the possibility to give to the system not the AOI vertices in some coordinate system but an example image In other words an AOI can be specified through an image portion selected in some way This approach is limited in the sense that is implemented only in the extraction tool and only for the quick look image Starting from the quick look image you can select a portion using IDL or XV or another image processing system capable to crop an image and tell to the system to retrieve the related coordinates In this way you will obtain the Top Left Bottom Right coordinates in row col system expressed in the full resolution reference ready to be used in the remaining tools without knowing anything about the coordinates just seeing the image and visually selecting the AOI 178 BEST User Manual v4 0 2 Appendix 5 Sequential Execution of Toolbox Algorithms The SAR Toolbox tools can handle INT files with multiple header sections in order to execute the various functions in a sequential way Using this technique the creation of processing cha
139. nal format data not generated by gain conversion oversampling complex data co registering complex data or importing raster data c when the operation takes place on internal format data generated by oversampling complex data co registering complex data or importing raster data mtn eA The image portion also called AOI area of interest can be specified in all the methods described in Appendix 4 40 BEST User Manual v4 0 2 HMI ba stbxw Full Resolution oi ae ASA_IM_ BPxPDE20020730_095830_ ASA_IMG_1PPDE20020730_095910_ ASA IMM 1PXxPDE 20020730 095830 ASA IMP_1PxPDE20020730 095910 1 header IMP HAN Typical HMI settings for an ASA_IMP_IP product Notes Select the product by means of the Input Media Path and the Header Analysis File HAN Typical Processing Chain HEADER ANALYSIS FULL RESOLUTION Example INI file FULL RESOLUTION Input Media Path D data ASAR DS1 ASA_IMP_1P 320 N1 Input Media Type cdrom Input Dir C BEST_out Output Dir C BEST_out Header Analysis File header_IMP HAN Output Image full_IMP 41 BEST User Manual v4 0 2 Top Left Corner 0 0 Bottom Right Corner 511 511 Parameter Summary Full Resolution Extraction Input Media Type The source media of the product tape Exabyte cdrom disk hard disk Example Input Media Type cdrom mandatory p
140. ned by the transformation function This interpolator does not work very well with complex data e Cubic Convolution uses five interpolations with a four coefficient cubic convolution kernel applied to the sixteen pixels around the position determined by the transformation function This is the interpolator that is used by default if no other interpolator is specified by the user However it should be noted that this interpolator does not work very well with complex data in such cases the sinc interpolator is recommended e Sinc the best and slowest interpolator uses a sinc kernel of size N applied N 1 times to the N by N pixels around the position determined by the transformation function The AOIs may be defined by the rectangular with corners expressed in row col or in lat lon coordinates or polygonal in this case the surrounding rectangular AOI is used methods The figures below show quick look images of an ASA_APM_1P product before and after geo correction 128 BEST User Manual v4 0 2 129 HMI BEST User Manual v4 0 2 A Input Dir Ic Input Image coherence CHf a full IMM x lt Ts full IMP XTs full IMS XTt zi Output Dir Sc F Output Image geo_IMM GC Interpolation Mode C Nearest Neighbour Bilinear Cubic Convolution Sine Parameters record file name ini file AOI spec H me gt F Typical HMI settings geo_IMM ini o for an ASA_IMM_IP product Typica
141. neither example image nor polygonal specification can be used optional parameter default is entire input image Window Sizes The size of the moving window used to compute the coherence expressed as row col Example window Sizes 5 5 mandatory parameter Output Image The name of the output image in internal format containing the coherence information an extension CHP is automatically added by the system Example Output Image cohe mandatory OUTPUT 124 BEST User Manual v4 0 2 BEST extension CHf 125 BEST User Manual v4 0 2 Footprint Registration Description The FOOTPRINT REGISTRATION tool generates a standard TIFF format quick look version of a master image superimposed with the outlines of one or many slave images This offers a fast method of assessing the suitability of images in a dataset for co registration purposes The tool uses an approximated method based on the corner localisation information from the Geolocation Annotation in the product headers to locate the slave image outlines relative to the master No AOL is permitted for this function Example INI file FOOTPRINT REGISTRATION Input Dir Output Dir Input Master Image asar_aps XTt Input Images slave_1 XTt slave_2 XTt Output Image Size 1485 490 Output Image footprint Delete Input Image N Parameter Summary Footprint Registration Input Master Image The name of
142. ng the file is called quick_look ini the tool would be run using the command BEST quick_look ini It is useful to examine the contents of the file quick_look ini to understand the meaning of the various instructions Many further details about the options available for the QUICK LOOK GENERATION tool can be found in the main section of the User Manual QUICK LOOK This is the name of the function The path to the directory containing the required Input Dir C BEST_out input files in this case the header file header_IMP HAN BEST User Manual v4 0 2 The path to a directory where the output files will be Output Di C BEST ENS NEED a out wrtitten This path directs the tool to the device and the product Input Media Path D data ASAR to be analysed In this case it is a CD drive mounted on the D drive Input Media Type cdrom The medium on which the data is held Header Analysis File header_IMP HAN The required input file for this function which contains information about the data product and was created by the HEADER ANALYSIS function The name of the output image file This will be in Output Quick Look Image ql_IMP ipo Q g A standard TIFF format with the extension tif added As above This version of the image has a grid Output Grid Image qlg_IMP superimposed on it The extension tif will be added The ori
143. nnotated antenna pattern and replaces it with another one 6 Rough range Calibration Corrects ASAR Wide Swath and Global Monitoring Mode images for the effect of incidence angle variation from near to far range 7 Enhancement Swath Corrects ASAR Wide Swath and Global Monitoring Mode products affected by intensity discontinuities between sub swaths 143 BEST User Manual v4 0 2 Backscattering Image Generation ERS Description The BACKSCATTERING IMAGE GENERATION tool is used to convert a power image into an image of backscattering intensity The output image may have either a linear or dB scale The following radiometric effects that could give a poor quality backscattering image can be corrected with this tool antenna pattern range spreading losses replica power variation ADC saturation effect The first two affect only SLC data which comes from the PAF in an uncorrected form The last two may affect the radiometry of any product The antenna pattern correction application or removal uses as input an Antenna Pattern File Nominal files for ERS1 and ERS2 are provided with the BEST software release located in the cfg directory although others can be created if required using the SUPPORT DATA INGESTION tool The reference replica power values used in linear scale are 205229 0 for ERS 1 156000 0 for ERS 2 The reference chirp average density values used are 267200 for ERS 1 201060 for ERS 2 When t
144. not important what format the data is in Output Image Scale The scale of the output backscatter image LINEAR DB 153 BEST User Manual v4 0 2 Do not use the dB scale if a further step of averaging is foreseen Example Output Image Scale LINEAR mandatory INPUT Output Image The name of the output image in internal format containing the retro calibrated data the extension BSf is automatically added by the system Example Output Image retro_IMP4399 mandatory INPUT BEST extension BSf 154 BEST User Manual v4 0 2 Rough Range Calibration ASAR Description The ROUGH RANGE CALIBRATION tool corrects an image for the effect of incidence angle variation from near to far range which is clearly visible in Wide Swath and Global Monitoring Mode products It can be applied either to amplitude or power images No AOI is permitted for this function Example INI file ROUGH RANGE CALIBRATION Input Dir C BEST_out Output Dir C BEST_out Input Image WSM XTs Output Image WSM_rough Parameter Summary Rough Range Calibration Input Image The name of an ASAR WS or GM image in internal format The input may be an amplitude or power image Example Input Image WSM XTs mandatory INPUT BEST extension APf PAT XTP IT GT OV UNf DBf OP SGf SGc FI C
145. nteger format to the floating point format 7 Ancillary Data Dump Generates an ASCII listing of the image annotations relating to an image in the Toolbox internal format 8 Image Operation Performs basic algebraic operations sum subtract multiply or divide between two images or between one image and a constant factor It is also possible to calculate the absolute value of a single image 9 Geometric Conversion Converts between row column and latitude longitude coordinates for points specified in any given image Also calculates the satellite s position and angles of incidence and look for the specified points 10 Slant Range to Ground Range Conversion Reprojects images from slant range range spacing proportional to echo delay to ground range range spacing proportional to distance from nadir along a predetermined ellipsoid The tool works on complex data extracted and or co registered SLC products and real data coherence products 11 Flip Image Executes a horizontal or vertical flip operation or both on any internal Toolbox format image 12 Sensitivity Vector Evaluation Calculates the sensitivity vector of an input image point by point 70 BEST User Manual v4 0 2 Gain Conversion Description The GAIN CONVERSION function operates on a floating point or 16 bit integer real image converting it to an 8 bit image This tool will often be used to convert the pixel values in an image into a range suitable
146. o by which the dimensions of the input image are transformed in the output image This parameter is an alter native to the Window Steps parameter Example Output Image Ratio 5 7 Window Steps The rate at which the local statistic kernel is moved set to a value different from 1 to sub sample the corresponding statistic image e g when computing a local statistic on a 100 by 100 image with a 10 by 10 kernel and a 20 by 20 step the output image will be only 5 by 5 pixels a step of 1 by 1 would generate a full image 91 by 91 pixels less than 100 by 100 because of the kernel edge effect This parameter is an alternative to the Output Image Ratio parameter Example Window Steps 2 0 3 0 Filler Value Should a polygonal AOI be used this specifies the value to be assigned to pixels in the output image always rectangular which do not fall within it Example Filler Value 1 0 optional parameter default is 0 Output Image The name of the output image in internal format containing the local statistic image Example Output File local_mean mandatory OUTPUT 102 BEST User Manual v4 0 2 BEST extension LSf 103 BEST User Manual v4 0 2 Principal Components Analysis Description The PRINCIPAL COMPONENT ANALYSIS tool generates the first and second principal component images from two input images The output images are scaled to avoid negative pixel values The AOI may only be defined
147. o decode the field The allowed formats are Strings Annn where nnn is any integer value that means a string of nnn characters or even a dummy field of nnn bytes Integer or floating numbers coded as strings In that means an integer field expressed using its ASCII representation with a fixed number n of digits For example if the 128 integer number has to be used to fill a I4 field the four characters will fill the field 1 2 8 and Fnn mm representing a real number expressed using its ASCII representation where nn and mm indicate respectively the number of digits before and 60 BEST User Manual v4 0 2 after the decimal point for example F16 7 means a real number of 16 digits 7 of which after the decimal point Dnn mm representing a real number in double precision expressed using its ASCII representation where nn and mm indicate respectively the number of digits of the entire number and after the decimal point for example D22 10 means a double of 22 digits 10 of which after the decimal point Enn mm representing a real number in exponential format expressed using its ASCII representation where nn and mm indicate respectively the number of digits counting also the E and the and sign of the entire number and after the decimal point Integer numbers in binary representation Bn that means a binary field of length n i e a sequence of n bytes with n equal to 1 2 or 4
148. oduct_type SLC geolocationgrid_tiepoints 11 165 geolocat geolocat iongrid_lstlinenum iongrid_totlinenum ct ct geolocat geolocat iongrid_samplenum iongrid_slanttime geolocat iongrid_incangle geolocat geolocat iongrid_latitude iongrid_longitude azimuth azimuth time_grid_mjd_days time_grid_mjd_seconds azimuth time_grid_mjd_microsec attachme subsatel product_ product _ swath_number polariza nt_flag_grid lite_track_heading name error IS2 tion_1l V V platform_h num_slic es 1 BEST User Manual v4 0 2 1 2446 4891 7336 9781 2445 2445 2445 2445 2445 1y 949 10377 19557 2073 2588 3209 5528476 500000 5555445 000000 18 670341 19 583149 20 449125 43932217 43956374 43979317 44001203 6346123 6196467 6053077 5915136 1848 1848 1848 1848 1848 35796 357577 359759 35 760 25 517081 996733 476385 956037 0 0 0 0 0 0 0 O 0 0 0 165 435593 165 448471 azimuth_time_dopp_mjd_days 1848 azimuth_time_dopp_mjd_seconds 35764 azimuth_time_dopp_mjd_microsec 561969 absolute_calib_k2 0 000000 x_sat_1 514699593 x_sat_2 516831736 x_sat_3 518954381 x_sat_4 521067490 x_sat_5 523171021 y_sat_l 83311311 y_sat_2 82871030 y_sat_3 82428006 y_
149. ogenous area of the image and compute the inverse to enter as a Gain value The figures below show a Global Monitoring product before and after swath enhancement The steps between adjacent sub swaths visible on the left are reduced in the corrected image Example INI file The following ini file is an example of swath enhancement for a Global Monitoring product ENHANCEMENT SWATH Input Dir C BEST_out 156 BEST User Manual v4 0 2 Output Dir C BEST_out Input Image GM1 XTs Output Image GMl_enh SW1 Gain 5 4925 SW2 Gain 2 197 SW3 Gain 1 69 SW4 Gain 1 3 SW5 Gain 1 SW1 end col 348 SW2 end col 500 SW3 end col 658 SW4 end col 778 Parameter Summary Swath Enhanacement Input Image The name of an ASAR WS or GM amplitude image in internal format Example Input Image GM1 XTs mandatory INPUT BEST extension Output Image The name of the output amplitude image in internal format containing the enhanced data the extension XT is automatically added by the system Example Output Image GMl_enh mandatory OUTPUT BEST extension XT SWn Gain n 1 2 3 4 5 The linear gain to be applied to swath n Example swi Gain 5 4925 mandatory parameter SWn end col n 1 2 3 4 The number counting from near range of the last column in swath n Example sSw1l end col 348 mandatory parameter 157
150. ogue box for each tool to be launched The tools are arranged as they are in the body of this User Manual according to the group to which they belong In addition there are menu groups for Environment Help and Exit some of the functions found here will be explained below jj astbxW ASAR Toolbox Br x Data Import and Quick Look Data Export Data Conversion Statistics Resampling Co registration Speckle Filter Calibration Environment Help Exit The Visual Basic HMI In many of the dialogue boxes there is a Show Default Values button This fills the fields in the dialogue box with typical or recommended values which may then be altered if required This is often a faster way to complete tool execution and reduces syntax errors Environment gt Set Environment Selecting Set Environment opens a dialogue box that allows the three environment variables required for installation to be set or reset quickly and easily 4 astbxW Set Environment Variable xj r Set ASTBX root installation directory Sc 7 Ch Software Path Cte arto Stbxhome C Software asartoalbox Flaafile Cota aratoabor otic Set Environment Variables Quit Select the root installation directory by browsing in the directory tree in the upper part of the dialogue box and then click on Set Environment Variables to automatically complete the three environment variables and write them to the syste
151. olor image data in several color spaces includes a number of image compression schemes is not tied to specific hardware is portable it does not favor particular operating systems file systems compiler or processors is designed to be expandable and evolve as new needs arise allows the inclusion of an unlimited amount of private or special purpose information allows the presence of any number of images in one file each with his own set of annotations A TIFF file is logically divided in two sections an annotations data part and an image data part The annotations are stored and retrieved in a TIFF file by their name i e the tag number This number is used as a entry for a table called IFD Image File Directory of pointers that show the zone of the TIFF file in which the annotations is kept In this way a change of the position of the parameters or the adding of further ones does not affect the capability to retrieve the data because all the read operations use this indexed mechanism For these reasons the TIFF format has a high tolerance to the annotations evolution position change new fields change of datatype for an annotation and so on een tae too IFD image section TIFF file 182 BEST User Manual v4 0 2 The pointers that show the zone of the TIFF file in which the annotations are kept The image section is kept in the TIFF as a sequence of strips that have the same columns as the original image an
152. ometric explanation The 116 BEST User Manual v4 0 2 forms of the warp functions for the four different degrees 1 1 5 2 or 3 are described in the Warp Evaluation chapter of the Algorithm Specification Document A3 Important As a simple rule when the input images do not suffer from a high level of distortion try first a degree of 1 or 1 5 This permits the evaluation of a smooth warp which is enough for the majority of cases and in particular should be sufficient for Tandem ERS data Larger values of the Transformation Degree parameter should only be used when a very good co registration accuracy is required Polynomials of second or third degree can introduce large distortions in image regions containing only a few GCPs In these cases it is advisable to use large numbers of GCPs especially in areas that are of particular interest to the user GCP Residuals The residuals the errors introduced by the warping function for each GCP are computed and written to a text file defined by the parameter Residual File Name This file also contains the warp coefficients generated by the co registration process It is often very useful to check the information contained within the residual file to see if the co registration process can be considered to have been successful For example the final figure shown in the file is the average RMS residual value referred to in the file as Total RMS This value can be used
153. on Description The SUPPORT DATA INGESTION function converts auxiliary data e g antenna pattern information or lookup tables for calibration from an ESA ASCII format into the Toolbox internal format This operation is only needed if a change to this data occurs and the auxiliary files included in the Toolbox need to be replaced Of course the user is free to ingest his own antenna patterns or ADC lookup tables Example INI files The following four ini files show how to transform the two antenna patterns and the two ADC lookup tables from the ESA format an ASCII file with two columns into the internal file format note that these files shall be kept in the cfg directory SUPPORT DATA Input Dir C best cfg Output Dir C best cfg Input Support Data File apersl dat Output Image apersi SUPPORT DATA Input Dir C best cfg Output Dir C best cfg Input Support Data File apers2 dat Output Image apers2 SUPPORT DATA Input Dir C best cfg Output Dir C best cfg Input Support Data File adcersl dat Output Image adcers1 SUPPORT DATA Input Dir C best cfg Output Dir C best cfg Input Support Data File adcers2 dat Output Image adcers2 Parameter Summary Support Data Ingestion Input Support Data File The external file in ASCII format Example Input Support Data File ersl_antpat dat mandatory INPUT
154. on has been cropped from a quick look image using a non Toolbox TIFF image processing tool the COORDINATES RETRIEVING BY EXAMPLE IMAGE function will determine the coordinates that define the cropped region within the original image The Coordinates Retrieving function compares two images an original quick look and a rectangular portion of it the example image cropped using an external TIFF image processing tool The system then returns the coordinates of two opposite corners of the example image expressed in the full resolution row column coordinate system of the original image This function is useful when the user wants to visually select an AOI using the quick look image in an external TIFF image processor without considering quantification By this method the coordinates of the AOI necessary for the FULL RESOLUTION EXTRACTION function are easily obtained The quick look versions with or without a superimposed grid can both be used but of course an original quick look with a grid cannot be compared with an example image without a grid or vice versa Some care must be taken with external TIFF image processing freeware used for cropping due to the presence of bugs and malfunctions For example the XV tool version 3 1 0 for Solaris2 has some problems when cropping a very small image if the number of columns of the cropped image is less than 72 an error occurs When an incorrect example image is input to the COORDINATES RETRIEVIN
155. one image by a constant the size of the resulting output image is given by the selected AOI of the input image or corresponds to the whole input image size if no AOL is selected The behaviour is different when adding subtracting multiplying or dividing two input images If no AOL is given the input images must have the same size This will also be the size of the output image When an AOL is given using this parameter settings Coordinate System LATLON Top Left Corner 41 160 14 830 Bottom Right Corner 41 130 14 800 or the following ones Coordinate System ROWCOL Top Right Corner 100 599 Bottom Left Corner 499 100 The AOI is always interpreted as the starting row starting column ending row and ending column of the first input image the master image This same AOI using the starting row starting column ending row and ending column resulting from the master image is applied to the other image the slave image A check is made to ensure that the dimensions of the second slave image are sufficient to contain the selected AOL In general it is suggested to always use rows and columns to set AOI because it is more difficult using a latitude and longitude system to ensure that the required area of interest lies within the boundary of the second slave image Image Operation Summary Table Parameter Description Comment Example the input image list one or two images mandatory INPUT Example IBEST ext
156. or an image or region of interest within an image Also generates a histogram of the pixel values 2 Local Statistic Generates output images showing a range of statistical parameters mean standard deviation coefficient of variation equivalent number of looks computed from an image using a moving window of selectable size 3 Principal Components Analysis Generates the first and second principal components from a pair of input images Resampling tools 1 Oversampling Up Sampling Resamples an image to increase the number of pixels 2 Undersampling Down Sampling Resamples an image to reduce the number of pixels Co registration and Coherence Generation tools 1 Co registration Registers one or more images to another using up to three separate processes to achieve a precise fit Images can be real or complex 2 Coherence Generation Calculates the phase coherence between two co registered complex images 3 Footprint Registration Indicates on a quick look of a master image the footprints of up to 10 co registered slaves 4 Image Geo correction Reprojects ASAR medium resolution imagery to a UTM or UPS planar grid 5 Amplitude Coherence Multi layer Composite Generates a multi layer pseudo true colour composite image consisting of the coherence between two co registered images with either their mean backscatter and the backscatter difference or the detected images of the master and slave BEST User Manual v4
157. put Dir C BEST_out n u HOH put Images pri_master XTt pri_slave XTt Output Images master slave Coordinate System ROWCOL Top Left Corner 100 200 Bottom Right Corner 1500 3000 GCPs Numbers 15 15 Image Coarse Reg N Image Fine Reg N Coarse Reg Window Sizes 101 101 Coarse Reg Interp Factors 3 0 3 0 Coherence Window Size 7 Transformation Degree 1 Overlapping Mode MIN Interpolation Mode SINC Baseline File Name basel txt Residual File Name residual txt 119 BEST User Manual v4 0 2 Parameter Summary Co registration Input Images The name of the input images in internal format to be co registered The master image is the first image specified A maximum of 10 images can be input All images must be of the same type Example Input Images mas XTt slal XTt sla2 XTt sla3 XTt mandatory INPUT BEST extension t s 22P 22c where indicates it is not important which module created the files as long as the data type is correct AOI specification see Appendix 4 no example image can be used Note that the AOI specification prevents the use of the minimum maximum and master overlap schemes optional parameter Output Images The names of the output images in internal format containing the co registered images an extension CRf or CRc is automatically added by the system
158. r Manual v4 0 2 Import Raster Image Description Using the IMPORT RASTER IMAGE function it is possible to convert external images not in the CEOS or MPHSPH format but having similar pixel size to the BEST internal file format Due to the fact that the function operates on pure image data no annotation is inserted into the output internal format image Therefore the number of BEST functions which can process the output from the IMPORT RASTER IMAGE function is limited Often the external images will include both a file header section once for the image and a line header for each line The raster import function is able to skip both header sorts to extract an output dataset containing only the image pixels instead of a mixture of pixels and header bytes Even if no direct AOI can be used it is possible to define a rectangular AOI using the following parameters e File Header Bytes e Line Header Bytes e Number of Rows e Number of Columns This function in allowing direct access to the media can be easily used to extract images with a corrupted or missing header Example INI file The following ini file is an example for a real raster image conversion the parameters are those used to convert a 500 rows by 500 columns portion of a CEOS PRI image file from an Exabyte tape unit on a Unix machine IMPORT RASTER Input Dir Output Dir Input Media Type tape Input Image dev rst1 Me
159. r equal than 35001 which is used in the internal format image as field identificator if a new tag has to be defined it has to be inserted in the include file TAGS H kept in the configuration directory CFG which contains all the correspondences between symbolic names and tag numbers some care must be taken in the usage of names and tag numbers not already defined Future Extension 1 reserved for future extensions Global Variable Assignment used to contain a reference to a global variable that will be assigned with the result of the evaluation of the field value section it is used to store temporary values that must be used during subsequent de formatting steps for example the number of records contained in a subsequent section such as the number of state vectors number of image lines and so on Future Extension 2 reserved for future extensions Future Extension 3 reserved for future extensions Field Name contains the detailed name of the field as appears in the header listing file obtained in the header decoding function Units contains the measure units of the field as appears in the header listing file obtained in the header decoding function 61 BEST User Manual v4 0 2 Comment contains a comment about the field as appears in the header listing file obtained in the header decoding function Naming conventions of the FDF files The name convention used to identify the various FDF files is mainly based on the restri
160. r example consider the following 4x3 filter 1 0 2 0 3 0 4 0 2 0 4 0 6 0 8 0 3 0 6 0 9 0 12 0 108 BEST User Manual v4 0 2 This could be synthesised by two 1 dimensional filters described by the following ASCII representation 1 0 2 0 3 0 4 0 1 0 2 0 3 0 109 BEST User Manual v4 0 2 Example INI file The following INI file shows the function working on a PRI image with an output image size defined in terms of pixels IMAGE UNDERSAMPLING Input Dir Output Dir Filter File Name usam33 ker Input Image priimage XTs Top Left Corner 100 200 Bottom Right Corner 399 599 Output Image undersam Output Image Size 200 200 The following INI file shows the function working on a PRI image with an output image size defined in terms of ratios IMAGE UNDERSAMPLING Input Dir Output Dir Filter File Name usam33 ker Input Image pri XTs Top Left Corner 100 100 Bottom Right Corner 299 399 Output Image undersam Output Image Ratio 5 7 This would give an output file of size 299 100 1 0 5 rows and 399 100 1 0 7 columns The following table describes the library of preset kernels 110 BEST User Manual v4 0 2 111 BEST User Manual v4 0 2 Undersampling Down Sampling Summary Table Example Input Image the name of the real input image in internal mandatory INPUT format BEST extension s 71 Example Input Ima
161. r has to supply a value here a string in accordance to the parameter type which becomes the value of Input Image parameter for the execution of the task having that line The syntax is allowed also for non string parameters as in the following sample line Constant Factor In this case the SAR Toolbox suspends the execution and prompts the following question Enter a NUMBER value for Constant Factor A richer definition makes it possible to put after the symbol a help string without blanks to be used when constructing the question This is useful especially for vector parameters So a line like the following Top Left Corner Row Column will give during the SAR Toolbox execution to two questions Enter a NUMBER value for Top Left Corner Row Enter a NUMBER value for Top Left Corner Column which are more clear than these two questions 185 BEST User Manual v4 0 2 Enter a NUMBER value for Top Left Corner Enter a NUMBER value for Top Left Corner which would be prompted in response to the following line where no help strings have been inserted after the symbol Top Left Corner The help string can also assist the user to supply a correct answer The answer related to a Yes No parameter to be supplied run time can be defined using a line like the following Delete Input Image Y N The question prompted from the SAR Toolbox is the following Enter a CHAR value for Delete Input Image
162. r standard masks this value is automatically com puted by the system but can be however overridden with this INI line For example Edge Threshold 0 82 the value of the threshold for the ratio optional parameter for masks this value should be computed using the relation showed in Speckle Filter chapter of the document for standard masks this value is automatically com puted by the system but can be however overridden with this INI line For example Line Threshold 0 87 The filtering masks are contained in ASCII files and their structure is governed by the following rules all the masks for the various regions edge line scatter filtering are kept in a unique ASCIII file all the masks shall have the same size which defines the filter size each row shall be terminated with a newline return character the first row of each mask shall indicate the mask type chosen between edgeline and scatter the mask identification as a progressive number between and the number of possible masks of a given type the symbols used for the pixel description shall be separated by one space character the symbol used to describe a left edge region is the 1 the symbol used to describe a right edge region is the 4 the symbol used to describe a line region is the the symbol used to describe a left buffer region is the 2 the symbol used to describe a right buffer region is the 3 139 BEST User Man
163. r takes the pixel nearest to the position determined by the warp function has an intrinsic accuracy of 0 5 pixel but is very fast e Bilinear uses three linear interpolations of the four pixel values around the position determined by the warp function This interpolator does not work very well with complex data e Cubic Convolution uses five interpolations with a four coefficient cubic convolution kernel applied to the sixteen pixels around the position determined by the warp function 117 BEST User Manual v4 0 2 e Sinc the best and slowest interpolator uses a sinc kernel of a selectable size N applied N 1 times to the N by N pixels around the position determined by the warp function This is the interpolator that is used by default if no other interpolator is specified by the user e Constant Shift in which each image block that has to be interpolated is shifted by a unique value determined by the interpolation grid by means of a FFT operation e Sinc along rows and Constant Shift along columns e Cubic Convolution along rows and Constant Shift along columns Important For complex images the bilinear and the cubic convolution interpolators do not work very well because they change the azimuth spectra of the images causing unwanted effects on images with low coherence Instead the constant shift at least in the row direction or the sinc interpolator is recommended because these are the only interpolators that preserve the imag
164. re input image Output Image The name of the output flipped image the extension FI is automatically added by the system Example Output Image vflp_img mandatory OUTPUT BEST extension FIf FIc Flip Mode The sense of the flip operation VERTICAL HORIZONTAL BOTH Example Flip Mode vertical mandatory parameter 95 BEST User Manual v4 0 2 Sensitivity Vector Evaluation Description The SENSITIVITY VECTOR EVALUATION tool calculates the sensitivity vector of an input image point by point The user may specify points one by one or alternatively define an equally spaced grid by its row and column dimensions The displacement measurable by radar using interferometry is the projection of a real displacement into the radar line of sight z If the displacement at a point d x y is represented in a local orthogonal frame of reference North East Vertical by 3 components d dy ds dy and the LOS between the radar and that point is represented in the same reference frame by the vector Z ZN ZE ZV the measured displacement at the point x y is given by the following scalar product D x y d x y amp y The vector z is called the sensitivity vector it gives a measure of the sensitivity of the measurement of displacement in each of three orthogonal axes For a given radar acquisition it varies with latitude and longitude within the scene A typical value
165. rectory with the following lines setenv BESTHOME BEST lt the home directory path see 2 above setenv FLAGFILE SBESTHOME flagfile setenv PATH BESTHOME bin SPATH If the login shell is the Bourne or Korn shell see 1 above modify the profile file found in the user s home directory with the following lines BESTHOME BEST lt the home directory path see 2 above FLAGFILE SBESTHOME flagfile PATH SBESTHOME bin SPATH export BESTHOME FLAGFILE PATH Exit from the current session and re login BEST is then ready to be run Check that the software is correctly installed by typing at the prompt the command best If the software is correctly installed you should see the following message BEST Generic Tool ver 3 0 beta best File ini not found The Tcl Tk HMI is launched by typing the command 21 BEST User Manual v4 0 2 besthmi If you haven t already done so you will need to download Tcl Tk from the Tcl Developer Xchange http www scriptics com and install it according to the accompanying instructions 22 BEST User Manual v4 0 2 6 HMI functionality The Visual Basic Human Machine Interface for Windows versions is launched by running the executable file c asartoolbox bin BESTW exe for example by double clicking its icon It consists of a set of menus that allow a dial
166. required GCPs This can be done for example using the QUICK LOOK GENERATION function with the grid in row col coordinates Another important use of this feature is the registration of ascending and descending pass images In this case the various image features are observed from different angles and are therefore very difficult to correlate One solution for this problem is to select as GCPs only high reflecting scatters or similar regions This can be done as explained before using the QUICK LOOK GENERATION function with the grid in row col coordinates The following example shows the format of the Specified GCP ASCII file simply composed of coordinate pairs from the master image defined in the row col coordinate system and separated by paragraph marks 100 200 244 772 844 902 1200 30 2309 4445 The Warp Function Once the valid positions of the GCPs in the slave image s are known a function is computed using a least squares method which maps the GCPs in the slave image onto the GCPs in the master image This function usually know as the warp function is used to perform the co registration The warp function is a polynomial in the row col coordinates with a degree defined by the parameter Transformation Degree This ranges from 1 which corresponds to a simple transformation which includes only translation rotation scaling and skew of the slave image s up to 3 which is a rather complex transformation with no simple ge
167. ric values k_b and k_a respectively The values k_b and k_a are obtained from the histogram of the image The user is required to select two percentage values Min Percentage and Max Percentage for example 1 and 99 5 The two radiometric values k_a and k_b are then calculated such that Min Percentage e g 1 of the image pixels have values below k_a and Max Percentage e g 99 5 of the image data have pixel values below k_b Pixels with values falling between the limits k_a and k_b have a linear stretch applied to them Pixels with values outside of this range are saturated at O and 255 An optional parameter Number of Black Levels can be used to exclude pixels with low values from the calculation which is used to evaluate the two radiometric values k_b and k_a If for example Number of Black Levels is set to 2 0 then all of those pixels with values lower than 2 0 are not included in the histogram on which the Min Percentage and Max Percentage levels are drawn The Number of Black Levels parameter allows the computation of a meaningful statistics even for images containing a large portion of pixels near or equal to zero In particular this is useful for obtaining a good image appearance for GEC or GTC products which contain large regions of black pixels due to the rotation that is applied to these images iii Look Up Table Mode In this mode the user is explicitly required to give the piecewise function that is used to stretch the image
168. rix holding in plane 0 1 and 2 each one of the RGB components ERMAPPER includes an import menu to load a TIFF image and transform it into its internal format see next paragraph This option can be also activated via the operating system shell with the following command importmany TIFF Image File ERMAPPER Image File The TIFF gray level image files are transformed into a one band ERMAPPER file while both RGB true color and Palette color images are always transformed into three band ERMAPPER image files 184 BEST User Manual v4 0 2 Appendix 8 Further INI File Issues setting values during run time and using the pipe capability The language for defining parameter values inside the INI file make it possible to set values run time during the execution of tools The usual rule lt parameter_name gt lt assign_symbol gt lt parameter_value gt where lt parameter name gt is the name of the parameter to be set lt assign gt is the symbol and lt parameter_value gt is lt string_value gt for STRING and CHAR parameters or lt number_value gt for INTEGER and REAL parameters also allows the symbol to be used in place of the lt string_value gt or lt number_value gt terms So when the SAR Toolbox encounters in an INI file a line like the following Input Image it suspends the execution and prompts the user with the following question Enter a STRING value for Input Image The use
169. rmat BEST extension t c Example here the indicates it Input Image slc_data XTt is not important which module created the files as long as the data type is AOI specification are permitted in row col or lat lon system see Appendix 4 for polygonal AOI the surrounding rectangular AOI is used modulus data an extension APf is auto matically added by the system IExample Output Image modul_data 79 BEST User Manual v4 0 2 Integer to Float Conversion Description The integer to float conversion function works on integer images generating the corresponding floating point image The only AOI which is permitted is the rectangular AOI with corners expressed in row col system Important Please note that the title of the function in the INI file is PIXEL TO FLOAT rather than INTEGER TO FLOAT This inconsistency will be changed in a later version of the SAR Toolbox Example INI file PIXEL TO FLOAT Input Dir Output Dir Input Image tl_priimage XTs Top Left Corner 0 0 Bottom Right Corner 799 799 Output Image float_img Integer to Float Summary Table Parameter Description Comment Example the name of the integer image in internal mandatory INPUT format BEST extension i s Example Input Image tl_pritmage XTs r t where the indicates it is not important which module created the files as long as the data type is AOI specif
170. s Top Left Corner 0 0 Bottom Right Corner 799 799 User LUT lut dat Output Image lutgain 74 BEST User Manual v4 0 2 Gain Conversion Summary Table Example the name of the real image in internal format mandatory INPUT Example EST extension 71 f Input Image tl_priimage XTs 2s here the indicates it Input Image AOI specification INumber of Black Levels ectangular or polygonal AOI specifications optional parameter if not are permitted in row col or lat lon system present the entire input see Appendix 4 for polygonal AOI the image is assumed surrounding rectangular AOI is used the constant used to scale the input pixel val mandatory parameter for ues the fixed gain conversion Scaling Factor 4 0 the percentage of data at low pixel values mandatory parameter for which shall be saturated to 0 in the output the variable gain stretch ing image excluding in this count the data havy mode ing a pixel value less or equal to Number of Black Levels Min Percentage 0 1 the percentage of data which will be scaled mandatory parameter for linearly excluding in this count the data hav the variable gain stretch ing ing a pixel value less or equal to Number of mode Black Levels and also the data sat urated to 0 by the parameter Min Per centage Max Percentage 99 8 starting level of the valid image pixels optional parameter for the values below this one are not considered variable gain
171. s v2 Output Image power_modulus 179 BEST User Manual v4 0 2 If one of the global parameters is also inserted in one of the INT sections it overrides the global setting but just for such section In the following example GLOBAL SETTING Input Dir Output Dir Temp Dir Delete Input Image Y COMPLEX TO AMPLITUDE Temp Dir tmp Input Image slcimage e5 Output Image modulus AMPLITUDE TO POWER Input Image modulus v2 Output Image power_modulus the temporary directory globally set to changes to tmp for the complex to amplitude conversion only 180 BEST User Manual v4 0 2 Appendix 6 System Performance and Memory Issues The parameters which affect the system performance of the SAR Toolbox system on the various machines are described here These parameters are all related to the main memory allowable to the SAR Toolbox This amount shall be carefully selected for multi user machines like the Sun or the DEC A too small amount of such memory imply that the SAR Toolbox system dimension its image buffer to a very little extent so requiring many disk access to cover the image processing action involved On the other hand if this size exceeds the physical memory allowable for the process the OS began to swap the memory on disk causing again loss of performances For single user machines like PC or Mac use the OS commands to measure the amount of free ph
172. sat_4 81982252 y_sat_5 81533782 z_sat_l 490448948 z_sat_2 488282118 z_sat_3 486106498 z_sat_4 483922126 z_sat_5 481729041 vx_sat_l 525233184 vx_sat_2 522903647 vx_sat_3 520564337 vx_sat_4 518215310 vx_sat_5 515856597 vy_sat_l 107880440 vy_sat_2 108556364 vy_sat_3 109228969 vy_sat_4 109898234 vy_sat_5 110564138 vz_sat_l 531511438 vz_sat_2 533676966 vz_sat_3 535832902 vz_sat_4 537979220 vz_sat_5 540115871 subimg_top_left_row 0 subimg_top_left_col 0 proc_history HEADER DECODE 29 Mar 2005 12 11 27 000 Mar 2005 16 10 46 000 pixel_type COMP LEX calib_const_appli_flag 0 adc_satur_compens_flag 0 chirp_average_density 0 000000 processing_paf unknown ASA_IMS_1PNUPA20050122_095556_000000162034_00065 FULL RESOLUTION 29 166 BEST User Manual v4 0 2 processor_name ASAR scaling_factor 1 000000 x_scale_factor 1 000000 y_scale_factor 1 000000 prf_equivalent 1652 491821 prf_equivalent_full 1652 491821 doppl_centr_cub_coeff 0 000000 replica_power_comp_flag 0 image_scale LINEAR data_format mph sph source_id esp number_of_volumes 1 row_transient 0 col_transient 0 presentation NORMAL nominal_replica_comp_flag 0 dopp_freq_degree 4 sensor_mode image full_image_length 26892 full_image_width 5175 The following table explains the annotations maintained by the BEST tools
173. ssumed by default if the Coor dinate System statement is not present the vertices are in the form V 1lat V 11on V2lat V2lon V nla t Vnlon the coordinate system statement must be present 175 BEST User Manual v4 0 2 Some care must be taken when using an AOI specified through the Top Right and Bottom Left corners in Latitude Longitude system for products which are not geocoded like the RAW SLC or PRI Lets look at a SAR image seen it in a geographical projection see figure PRI seen in a geographical chart When you select the two corners TL and BR you are thinking of the AOI shown in What the user was thinking but due to the fact that the range axis is not parallel neither to the latitude neither to the longitude axes you could obtain the AOI shown in What the user could obtain This happens because the system converts the two corners coordinates from lat lon to row col and then uses these to extract the related AOI 12 w 16 he 16 PRI seen in a geographical chart 176 BEST User Manual v4 0 2 What the user could obtain To avoid these problems an ad hoc management of such situations has been developed For all tools except the Statistical tool with the local statistic the AOI obtained is the same as in the figure what the user could obtain i e the rectangular area with sides parallel to the range and azimuth axes having the specified TL and BR corners and a warning
174. stretching during the histogram evaluation mode shall be avoided for Number of Black Levels 1 0 the remaining conver sions the name of the ASCII file containing the mandatory parameter for lookup table used to stretch the image in the the user lookup table lookup mode stretching mode User LUT lut dat the name of the output image in internal mandatory OUTPUT format containing the image converted in 8 BEST extension GCi bit pixel modulus data an extension GCi is automatically added by the system Example Output Image cnvt_image 75 BEST User Manual v4 0 2 Power to Amplitude Conversion Description The POWER TO AMPLITUDE CONVERSION tool takes the square root of the input image pixel values thus generating a floating point image representing the amplitude of a power image In the output image annotation the pixel type is set to amplitude so that those tools that need amplitude data as input data can first execute a check The only AOI permitted is the rectangular AOI with corners expressed in row col Example INI file POWER TO AMPLITUDE Input Dir C BEST_out Output Dir C BEST_out Input Image power_data APf Output Image ampl_data Parameter Summary Power to Amplitude Conversion Input Image The name of the input real image in internal format Example Input Image power_data APf mandatory INPUT BEST extension f where indicates t
175. t used for the quick look image Important It is not possible to open the TIFF files generated by BEST with all image viewing software For PC platforms you should not encounter any problems using Adobe Photoshop Jasc Paint Shop Pro or Microsoft Paint a standard component of Microsoft Windows found in the Start Menu under Programs gt Accessories gt Paint For Solaris2 platforms using XV it is necessary to launch the software first and then load the image from the browser Typical Processing Chain HEADER ANALYSIS gt QUICK LOOK GENERATION gt IMAGE PREVIEW gt FULL RESOLUTION EXTRACTION Example INI file IMAGE PREVIEW Input Image quicklook tif Coordinate System ROWCOL Start Column 100 Start Row 100 End Column 600 End Row 600 Output Image preview Parameter Summary Image Preview Input Image The name of the full quick look image the version with or without a grid can be used Example Input Image quick look tif mandatory INPUT BEST extension tif AOI specification See Appendix 4 mandatory parameter Output Image The name of a standard TIFF image to be written with a quick look of the specified AOI the extension tif is automatically added by the system Example Output Image preview mandatory OUTPUT BEST extension tif 45 BEST User Manual v4 0 2 Coordinates Retrieving by Example Image Description If a regi
176. ted from the two co registered images Example Image Lower Threshold 18 optional parameter default is 22 Image Upper Threshold The upper limit in dB for logarithmic scaling of the average modulus backscatter computed from the two co registered images Example Image Upper Threshold 2 5 optional parameter default is 3 5 Difflmage Lower Threshold The lower limit for linear scaling of the ratio in dB of the two co registered modulus backscatter images Example DiffImage Lower Threshold 2 optional parameter default is 1 Difflmage Upper Threshold The upper limit for linear scaling of the ratio in dB of the two co registered modulus backscatter images Example DiffImage Upper Threshold 5 133 BEST User Manual v4 0 2 optional parameter default is 6 User LUT The name of an ASCII file containing the lookup table used for further stretching of the 8 bit layers Example User LUT lut dat optional parameter 134 BEST User Manual v4 0 2 13 Speckle Filter This chapter documents the following tools 1 Speckle Filter Removes speckle noise from real intensity images using the Gamma MAP algorithm 135 BEST User Manual v4 0 2 Speckle Filter Description The speckle filter tool removes speckle noise from intensity images using the Gamma MAP algorithm This is provided in the SAR Toolbox because removing the speckle noise from a SAR image is an import
177. ted the files as long as the data type is correct 106 BEST User Manual v4 0 2 AOI specification only the Rectangular AOI specifications are optional parameter if not permitted see Appendix 4 present the entire input images are assumed the size of the output image expressed as This parameter is an alter number of rows number of columns these native to Output Image sizes shall be greater than the input image Ratio size this number permits to control the over sampling factor Output Image Size 2000 1500 Output Image Ratio The row col ratios to determine the size of This parameter is an alter the output file These numbers should be native to Output Image greater than 1 Size Output Image Ratio 1 5 1 1 the name of the output image in internal mandatory OUTPUT format containing the oversampled image an BEST extension extension OVf or OVc is automatically OVfor OVc added by the system Output Image oversam 107 BEST User Manual v4 0 2 Undersampling Down Sampling Description The undersampling function down samples a real image like a PRI or GEC product using a kernel which moves across the input image with a step size determined by the size of the required output image The size of the output image can either be determined by specifying this directly in terms of the pixel dimensions e g Output Image Size Or in terms of the row col ratios by which the input image should be multiplie
178. ter indicates the format of the pixel data following the convention 8 bit integer 16 bit integer complex integer 16 bits 16 bits 32 bit float complex float 32 bits 32 bits naman e RAW products integer 8 bits 8 bits Data Import and Quick Look Statistical Header Analysis HAN txt Global Statistic txt Media Analysis txt Local Statistic LSf Quick Look Generation if Principal Component Analysis PCf Full Resolution Extraction XT R line Portion Extraction XT mae me Image Preview tif Oversampling Up Sampling OV Coordinates Retrieving by Example txt Undersampling Down Sampling Unf a a Co registration and Coherence Generation mport Geo GT BE 9 Import TIFF IT Co registration n XTf I t Raster I 16 bit dat RI ih ber Reiter Tunes n ael Coherence Generation CHf mport Raster Image 16 16 bit data RIt f Footprint Registration tif Data Export Image Geo correction GRf Export GeoTIFF tif Amplitude Coherence Composite tif oe a ne Radiometric Resolution Enhancement an Bi BE Speckle Filter SFf Export to RGB if Calibration Data Conversion Backscattering Image Generation BSf Gain Conversion GCi pas p on ER Power to Amplitude Conversion PAf amma mage Seneranon i Ampli Retro calibration BSf mplitude to Power Conversion APf Be scott Rough Range Calibration XTf Linear to dB Conversion DBf Swath Enh XTf Complex to Amplitude Conversion CAf a ru i Integer to
179. the following example the output image size is determined by the parameter Output Image Ratio The output image local LSf will have 299 100 1 0 5 rows and 399 100 1 0 7 columns LOCAL STATISTIC Input Dir Output Dir Input Image pri XTs Output Image local Output Image Type MEAN Output Image Ratio 5 7 window Sizes 3 5 Top Left Corner 100 100 Bottom Right Corner 299 399 101 BEST User Manual v4 0 2 Local Statistic Summary Table Input Image The name of the input real image in internal format Example Input Image tl_priimage XTs mandatory INPUT BEST extension s 1 2 f where indicates it is not important which module created the files as long as the data type is correct AOI specification see Appendix 4 optional parameter default is entire input image Output Image Type The type of local statistical operation MEAN moving mean SDDV moving standard deviation CFVR moving coeffi cient of variation_ ENLV moving equivalent number of looks Example Output Image Type MEAN mandatory parameter Window Sizes The size of the kernel used to compute the local statistic a couple of integer numbers comma separated the first one referring to the number of rows the second to the number of columns Example Window Sizes 5 5 mandatory parameter Output Image Ratio The rati
180. the number of files in each volume the number of records in each file and the number of bytes in each record for products held on Exabyte media 3 Quick Look Generation Generates a reduced resolution approximation of an image directly from the original data product or from an internal format file 4 Full Resolution Extraction Extracts a full resolution portion of an original data product to the internal file format 5 Portion Extraction Extracts a full resolution subset of an image already in the Toolbox internal format 6 Image Preview Extracts a region of interest from a quick look image This function is useful to verify that a region of interest is correctly defined before it is extracted at full resolution 7 Coordinates Retrieving by Example Image Derives the coordinates within a scene that define a subset or region of interest as extracted from a quick look image and saved as a second tif file using another image viewing tool 8 Support Data Ingestion Converts support data e g antenna pattern information or lookup tables for calibration from an ESA ASCII format into the Toolbox internal format 9 Import GeoTIFF Converts a GeoTIFF image into the Toolbox internal format 10 Import TIFF Converts standard TIFF files to the Toolbox internal format 11 Import Raster Image Converts an image in raster format into the Toolbox internal format without having to specify the number of file header bytes or line header b
181. ting system pipe capability it is possible to create files containing the answers related to the symbols inserted into a INI file and so further automate the execution If we consider the previous example we may create a file containing several lines each one containing some input data e g a file GC2TIFF PAR may contain the following 109 XTs 1 0 99 0 109 The SAR Toolbox Generic Tool can be run using the following command cat GC2TIFF PAR stbx GC2TIFF INI on UNIX machines or the following command type GC2TIFF PAR stbx GC2TIFF INI for PC machines Moreover on UNIX machines having a collection of input files each containing a different set of parameter values to be given as input to the same INI file it is possible to create inside a C shell a file like this bin csh foreach m GC2TIFF PAR cat m stbx GC2TIFF INI end which at execution time will look at all the files GC2TIFF PAR and for any file matching this pattern run the SAR Toolbox Generic Tool using the value of the instanced variable m This means that having ten files GC2TIFFO PAR GC2TIFF9 PAR each created with appropriate data in the directory where this C shell file is executed the SAR Toolbox is run ten times each time with one of the different matched files Using this technique will help to avoid the need for the intervention of the user A similar feature cannot be directly implemented using the DOS operating system It is ho
182. ual v4 0 2 The following listing shows the standard mask file of size 11 edgeline 1 11112 34444 11112 34444 11112 34444 11112 34444 11112 34444 11112 34444 11112 34444 11112 34444 11112 34444 11112 34444 11112 34444 edgeline 2 44444444444 44444444444 33444444444 334444444 22 3334444 1122 3344 11 1 7222 33 111111122 11111111122 11111111111 11111111111 edgeline 3 11111111111 11111111111 11111111122 111111122 B ED Lebar Se 1122 3344 22 3334444 334444444 33444444444 44444444444 44444444444 edgeline 4 3444444444 2 344444444 12 34444444 112 3444444 1112 344444 11112 34444 111112 3444 1111112 344 11111112 34 111111112 3 1111111112 edgeline 5 140 11111111111 11111111111 11111111111 11111111111 22222222222 33333333333 44444444444 44444444444 44444444444 44444444444 edgeline 6 1111111112 111111112 3 11111112 34 1111112 344 111112 3444 11112 34444 1112 344444 112 3444444 12 34444444 2 344444444 3444444444 edgeline 7 1111112 344 1111112 344 111112 3444 111112 3444 11112 34444 11112 34444 11112 34444 1112 344444 1112 344444 112 3444444 112 3444444 edgeline 8 112 3444444 112 3444444 1112 344444 1112 344444 11112 34444 11112 34444 11112 34444 111112 3444 111112 3444 1111112 344 1111112 344 BEST User Manual v4 0 2 141 BEST User Manual v4 0 2 scatter 1 The user masks can be built in an analogous way The most important thing to remember when build
183. uct Add na nissen Ee aetna e E Oe nates 55 8 Data EXOT iine iaaa a a ri E ge 63 Export G o TIFE aeos onna dee e a Gai 0 Saale pt a a a Sau aa nee 64 Export to TIFE ar ei aaa elek EETIKA cadedee ai 65 EOE Te B Ua Fo pee ar ne a dee et 67 Export to ROBIN ME Seeds 69 9 D t Conversion ee alerts aI E 70 Gain Conversion nina Ea ESEA EASE E EErEE EE Ee EnS 71 Power to Amplitude Conversion usiekseiienste else 76 Amplitude to Power Eonvesion a a 77 Linear to dB CONV Gr Stn 2 euere 78 Complex to Amplitude Conversion asus ensemble 79 Integer to Float Conversion seeesesssereesssersssrressssrresrssteesssereessseresssereessseteesssereesssrreesseeee 80 Ancillary Data DUMP na a ieee ete ar 81 Image Operati M as aban sass lausaceyeoangreehied rns ep ae E RETE eee 83 Geometric Conversion cesis aiki EKET TKEK Gin Garda IREKE AESA Siak 87 Slant Range to Ground Range Conversion ccccceeeeeeessneececeeeeeeseseennaeeeeeceeeeseesnnnaeeeeeeees 91 Flip Imape eisen ASA E A E S R EKS al EASE SES a 94 Sensitivity Vector Evaluation sssseessssseessssressssrresrsererssserersssrreessereessserersrsereesssrressseree 96 BEST User Manual v4 0 2 TOSS AUISTICAL sascha E EE E E A E E A era 98 Global Statisti u rien 99 Local SUAS UNG So le ae nr as A EES 101 Principal Components Analysis heulen 104 Ti Resamplin esse einer essen divunceadiatecleuntoncdisaals 105 Oyessamplinge Up Sampline cankia dete sites Gamat ia han ik lsaslikeikke
184. ult is Y for complex data and N for real data Fine Reg Window Sizes The size of the cells used for the fine registration step expressed in row col Each cell is centred on one of the GCP positions and the coherence maximisation or cross correlation refinement is performed within it Example Fine Reg Window Sizes 51 51 optional parameter default is 51 51 Coherence Threshold Threshold below which GCPs are excluded from the co registration calculation Example Coherence threshold 0 4 optonal parameter Coherence Window Size The size of the square kernel used for the coherence evaluation in the fine registration step expressed as the length of one side in pixels Example Coherence Window Size 7 optional parameter default is 3 Coherence Func Tolerance 121 BEST User Manual v4 0 2 A stop criteria for the iterative searching during coherence maximization When coherence changes fall below this tolerance the search stops Example Coherence Func Tolerance 1 e 6 optional parameter default is 1 e 6 Coherence Value Tolerance A stop criteria for the iterative searching during coherence maximization When the shifts in units of pixels made on the slave cell fall below this tolerance the search stops Example Coherence Value Tolerance 1 e 3 optional parameter default is 1 e 3 Transformation Degree The degree of the warp transformation polynomial a 1 5 ae
185. umber of bytes to skip once at the beginning of the image data file typically these bytes constitute the file header section before the image data itself Example File Header Bytes 16012 optional parameter default is 0 Line Header Bytes The number of bytes to skip at the beginning of each image line typically these bytes constitute the header section of each line and contain non image data Example Line Header Bytes 12 optional parameter default is 0 Image Record Length The length of the image data file expressed as number of bytes Example Image Record Length 16012 mandatory parameter Number of Rows The number of rows of the input image to be imported Example Number of Rows 500 mandatory parameter IF Input Media Type is set to tape optional parameter in the remaining cases default is entire image Number of Columns 53 BEST User Manual v4 0 2 The number of columns of the input image to be imported Example Number of Columns 500 optional parameter default is entire image Swap Bytes A flag indicating whether the order of each byte couple shall be swapped before writing in the output file Use Y to execute the swapping when reading a CEOS product which is stored in a NONDEC format with a PC set to N to leave the byte ordering untouched when reading a MPHSPH product which is stored in DEC format with a PC PCs are DEC ordering machines Example Swap Bytes y opt
186. umns right Quick look of the ground projected image 2614 columns same number of rows Typical Processing Chain The SLANT TO GROUND RANGE CONVERSION tool may be used as part of a processing chain to generate a multi looked PRI like image in ground range starting from an SLC product Several steps are necessary to perform multi looking on an SLC image as described below oversampling 2 x 2 in SLC format zero padding avoids aliasing problems slant to ground range re projection in SLC format look detection amplitude image look adding by undersampling with the desired multi look factor The corresponding processing chain in terms of tools in BEST would be HEADER ANALYSIS FULL RESOLUTION gt OVERSAMPLING gt SLANT TO GROUND RANGE CONVERSION gt COMPLEX TO AMPLITUDE CONVERSION gt UNDERSAMPLING gt EXPORT The OVERSAMPLING Output Image Ratio should be 2 2 The UNDERSAMPLING Output Image Ratio should be 0 166 0 5 for a 3 look output However to improve computational performance it is advised to apply slant to ground range re projection to the amplitude image by rearranging the processing chain thus HEADER ANALYSIS FULL RESOLUTION gt OVERSAMPLING gt COMPLEX TO AMPLITUDE CONVERSION gt UNDERSAMPLING gt SLANT TO GROUND RANGE CONVERSION gt EXPORT Important Oversampling a full SLC scene from ERS or Envisat will increase the file size above the maximum 2Gb allowed for TIFF
187. utput Coordinates Type LATLON Output File geoconv Output file geoconv txt STB BEST ToolBox Telespazio ESA GEOMETRIC CONVERSION Reference Image dat i09 XTs ROW COLUMN gt LATITUDE LONGITUDE 0 0 gt 41 188416 14 906085 100 0 gt 41 199415 14 909317 OUT OF IMAGE 999 999 gt 41 102253 14 728530 1999 0 gt 40 968536 14 841642 OUT OF IMAGE 100 250 gt 41 183374 14 866438 150 250 gt 41 177875 14 864826 To convert row column to incidence look angle In this case the tool is used to compute incidence angle and look angle for a series of row column pairs Note that for demonstration purposes two of the specified points lie outside the reference image under consideration GEOMETRIC CONVERSION Reference Image 109 XTs Input Coordinates Type ROWCOL Input Coordinates 0 0 100 0 999 999 1999 0 100 250 150 250 Output Coordinates Type INCLOK Output File geoconv Output file geoconv txt STB BEST ToolBox Telespazio ESA GEOMETRIC CONVERSION 88 BEST User Manual v4 0 2 Reference Image dat 109 XTs ROW COLUMN gt INCIDENCE ANGLE LOOK ANGLE 0 0 gt 20 273800 17 952206 100 0 gt
188. wever possible to collect inside a Batch file named e g GC2TIFF BAT all the sequences of SAR Toolbox activation command as in the following example type GC2TIFFO PAR stbx GC2TIFF INI type GC2TIFFO PAR stbx GC2TIFF INI type GC2TIFF9 PAR stbx GC2TIFF INI 188 BEST User Manual v4 0 2 The FOR command of the DOS operating system may help to create this file In fact instead of extensively writing all these lines it is possible to create the GC2TIFF BAT running from the Prompt MS DOS shell the following commands DEL GC2TIFF BAT FOR m IN GC2TIFF PAR DO ECHO TYPE m stbx GC2TIFF INI gt gt GC2TIFF BAT The first command line is needed to be sure that redirection happens in empty file The symbol in the second command line is used in place of to suspend pipeline activation At the end it is only necessary edit the GC2TIFF BAT file and search and replace all occurrence with the symbol Finally to execute all command inside the GC2TIFF BAT file is only needed to run from the DOS shell the following command GC2TIFF BAT Finally no kind of pipe capability exists on MacIntosh machines 189
189. xample Input Image pri APf mandatory INPUT BEST extension APf AOI specification See Appendix 4 the example image mode is not permitted 145 BEST User Manual v4 0 2 optional parameter default is entire input image Antenna Pattern Correction Determines whether the antenna pattern compensation factor shall be applied APPLY or removed REMOVE from the image if the parameter is omitted this correction is not considered at all neither applied nor removed Example Antenna Pattern Correction APPLY optional parameter default is no correction Antenna Pattern File The name of the internal format file containing the antenna pattern Example Antenna Pattern File ers2 SDf mandatory INPUT if Antenna Pattern Correction is set to APPLY BEST extension SDf Range Spreading Loss Correction Determines whether the range spreading loss compensation factor shall be applied APPLY or removed REMOVE from the image if the parameter is omitted this correction is not considered at all neither applied nor removed Example Range Spreading Loss Correction APPLY optional parameter default is no correction Replica Power Correction Determines whether the replica power variation compensation factor shall be applied APPLY or removed REMOVE from the image if the parameter is omitted this correction is not considered at all neither applied nor removed
190. xtensions The majority of Toolbox functions operate on data that has been converted into the Toolbox internal format Therefore it is always necessary to first read new data into the Toolbox format using the Data Import tools see Chapter 7 All Toolbox operations produce output data in the internal format and assign filename extensions that identify the tool used and the data type see Chapter 4 BEST User Manual v4 0 2 2 Three Simple Examples The purpose of this chapter is to provide three simple examples of the most basic BEST functions Hopefully this will help to demonstrate the way in which the Toolbox works so that you can use it more effectively according to your own needs In these examples header information is read from the data a quick look image is generated and a portion of the data is read onto disk Header Analysis Before any processing can be performed on data using BEST including quick look generation or data extraction the HEADER ANALYSIS module must be run to extract into an internal format file the header information contained in the product or accompanying file The ASCII ini file generated to run the tool may look something like this HEADER ANALYSIS Output Dir C BEST_out Input Media Path D data ASAR DS1 ASA_IMP_1P 320 N1 Input Media Type cdrom Sensor Id ASAR Sensor Mode Image Product Type PRI Data Format ENVISAT Source Id
191. ype the sensor Id the source PAF is obtained by a comparison of the media structure obtained scanning the media CDRM or EXABYTE with a file containing the nominal values of this structure for the various products This file has then as many entries as the number of products which are different each other in their media structure Obviously if two product have the same media structure there is no way to guess the format type sensor and PAF In the next page is showed a listing showing the nominal media structure file 55 BEST User Manual v4 0 2 A typical entry is the Nominal Media Structure File has the following structure PRODUCT PARAMETERS SECTION VOLUME SECTION VOLUME SECTION 2 VOLUME SECTION N Within the PRODUCT PARAMETERS SECTION the structure is product_type SENSOR sensor_id FORMAT format_id SOURCE source_id where product_type can be one of the following three character strings SLI stands for SLCI product RAW SLC SLI PRI GEC GTC sensor_id can be ERS1 or ERS2 or in general a four character string XXXN the various sensors are distinguished only by the last character N of their conventional name so avoid using ERS1 and ENV as two different sensors format_id can be CEOS or MPHSPH or in general a n character string FXX X the various formats are distinguished only by the first character F so avoid using CEOS and CGM as two different formats source_id can be ESP for ESRIN products DEP
192. ysical memory If you are in doubt select few Mbytes less than the amount of installed physical memory The system INT file is listed below and is the same for all the machines so you have to modify just the section related to your computer The memory amount is expressed in kbytes SUN System Memory 16384 SGI System Memory 16384 HP System Memory 16384 OSF System Memory 16384 IBM System Memory 16384 DOS System Memory 16384 WIN95 System Memory 16384 MAC System Memory 16384 181 BEST User Manual v4 0 2 Appendix 7 The SAR Toolbox Internal Format The internal format adopted in STB is called TTIFF which stands for Tiled Tagged Image File Format The TTIFF format is a particular form of the TIFF format and is very similar to the internal format of the Italian PAF products which is called BTIFF Blocked Tagged Image File Format The slight differences are essentially associated with the name of some image parameters which in the TIFF world are called tags and with some restrictions in the image organization To clarify the topic a brief description of TIFF BTIFF and TTIFF formats follows The TIFF format is a image file format used mostly for the PC Desktop Publishing applications for encouraging the exchange of digital images between the various packages The main features of the TIFF format are capable to describing bi level greyscale palette color and full RGB c
193. ytes Also generates an ASCII file containing the image size information which is compatible with the ERMAPPER ers format 12 New Product Adding 26 BEST User Manual v4 0 2 This is not really a function in the same sense as the other tools However these pages describe how it is possible to recognise and decode SAR products that were not previously recognised as standard products 27 BEST User Manual v4 0 2 Header Analysis Description The HEADER ANALYSIS function decodes all the header parameters from a product on tape CD ROM or hard disk This information is extracted and stored in a plain ASCII file extension txt and in a file in the Toolbox internal format extension HAN The ASCII file can be examined using a standard text editor to provide useful information about the data An example of one of these ASCII files is provided in Appendix 1 The Toolbox has been designed to handle ESA data products from both the Envisat ASAR instrument and the AMIs on ERS 1 amp 2 Level 1b ASAR data acquired in Image Mode Wide Swath Mode Alternating Polarization Mode or Global Monitoring Mode may be input along with ERS image data RAW SLC SLCI PRI GEC or GTC The Toolbox handles the standard Envisat product file format For ERS data products generated within the ESA ERS ground segment at D PAF I PAF UK PAF and ESRIN are supported plus data from non ESA PAF stations if they are delivered with ESA CEOS annotations

Basic Envisat SAR Toolbox

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