Special report 16 - Digital Conservancy
Contents
1. Gn Bete 5 0 S 6 TO ACE NGE ERDAS PROG El EPPL7 DATA FILES Sat Shans Weg TS 066 or 51 YLO SINNI 40 ALISUBAIN _ Wa WATER RESOURCES RESEARCH CENTER Wasa UNIVERSITY OF MINNESOTA Waag ST PAUL MN 55108 Bisa Special Report No 16 June 1987 ACKNOWLEDGEMENTS This report is part of a larger project supported by funds from the Legislative Commission on Minnesota Resources and supervised under contract with the Department of Natural Resources We gratefully acknowledge several individuals for their contribution to the development of this computer program Dwight Brown Phil Gersmehl and Dick Skaggs of the Geography Department supervised the development of this program and provided access to the necessary computer equipment Les Maki Paul Tessar Pete Olson and Steve Anderson of the Minnesota Planning Information Center provided up to date copies of the EPPL7 program and documentation for our scrutiny and managed to keep an open ear to our comments Bruce Rado and countless other staff members at ERDAS kept our hardware and their software in operation through the years beginning with an early model ERDAS 400 which the Geography Department only recently retired and currently with our IBM AT Phil Voxland of the University s Social Sciences Research Facilities Center answered a number of picky technical questions regarding FORTRAN on an IBM2. AT Jim Young of the Geography Department was good natured about testing our software documentation IBM PC XT AT PC DOS CGA 1 EGA and PGA are registered trademarks and products of the International Business Machines Corporation MS is a registered trademark MS DOS is a registered product and FORTRAN 77 Version 8 31 is a copyright product of Microsoft Corporation ERDAS is registered trademark and copyright product of ERDAS Inc Atlanta Georgia EPPL7 is a copyright computer program of the Planning Information Center Minnesota State Planning Agency DEC and VAX are registered trademarks and products of the Digital Equipment Corporation SideKick is a trademark and registered product of Borland i International Landsat refers to a series of satellites originally launched by the U S Geological Survey and the National Aeronautics and Space Administration Current Landsat satellites are under operation of EOSAT Inc Lanham Maryland Water Resources Research Center The Graduate School The University of Minnesota _ PATRICK L BREZONIK Director ELIZABETH ESPOINTOUR Secretary This is number sixteen WRRC Special Report series The Center also publishes technical reponi and a newsletter A publication list is available from the WRRC The University of Minnesota is committed to the policy that all persons shall have equal access to its programs facilities and employment without regard to
3. create an ERDAS file from an EPPL7 file During this conversion the user will be kept informed of the progress Copying EPPL7 file to ERDAS file Processing Row 1 The Processing Row message will be updated with each new row It is not uncommon for data files to take several minutes to be converted When the conversion of the data file is complete the display will read ERDAS File has 500 rows and 417 columns Copying EPPL7 file to ERDAS file Processing Row 500 Done After this conversion the user will have the opportunity to create an ERDAS Trailer file TRL from its equivalent EPPL7 Color Table CLR and Legend LEG files Do you want to build the ERDAS Trailer TRL file or If the user responds with yes Y the program will create the ERDAS Trailer file The program assumes that the Trailer file should be created using the same file name as the ERDAS data file e g SOILS TRL for the SOILS GIS The EPPL7 Color Table and Legend files are assumed to have the same name as the EPP data file Do you want to build the ERDAS Trailer LTRL file or Writing COLOR TABLE to the Trailer File Writing HISTOGRAM to the Trailer File Writing LEGEND to the Trailer File Following the successful creation of an ERDAS Trailer file the program returns to the main menu If the user responds to the request with no N the program goes immediately b
4. file each class in the GIS file represents an intensity value from 0 to 127 WRRC U OF Minn Special Report Sixteen 8 The number of rows and columns in the file will be displayed followed by the current line being converted by the program For the ERDAS SOILS demonstration file this message will read ERDAS File has 500 rows and 417 columns Copying ERDAS file to EPPL7 file Processing Row 1 The Processing Row message is updated with each new row that is converted to EPPL7 format It is not uncommon for data files to take several minutes to be converted All ERDAS files converted to the EPPL7 will have Class 0 declared as the offsite or background the normal value on the ERDAS system When the conversion of the data file is complete the display will read ERDAS File has 500 rows and 417 columns Copying ERDAS file to EPPL7 file Processing Row 500 Done The user now has the opportunity to convert the ERDAS Trailer file TRL to its equivalent EPPL7 Color Table CLR and Legend files Do you want to convert the ERDAS Trailer TRL file Y or N You should select this option only if an ERDAS GIS file was converted by this program ERDAS Landsat files do not have a Trailer file The program automatically assumes that the Trailer file is to be created using the same file name as the ERDAS data file SOILS TRL for the SOILS GIS fil
5. for the ERDAS file Class values in the EPPL7 file must also represent intensity values between 0 and 127 to work properly as a Landsat file If either file cannot be found the program will request a different filename from the user Make sure that the proper disk drive is specified for each file You do not need to enter the disk drive letter or subdirectory designation if it is the same as the default drive specified in the DOS prompt After the files have been located the program will read the header record of the EPPL7 file to obtain the number of lines and columns These values are displayed for the users benefit For the SOILS demonstration file this message will read EPPL7 File has 500 rows and 417 columns To properly convert an EPPL7 file to the ERDAS system the EPPERD program must know the value for the highest category in the GIS file This valuc controls the form of data packing used in the ERDAS file plus is stored as part of the ERDAS header record The user must enter the value in response to the following question What is the HIGHEST CLASS number in the file 0 255 This number is usually determined using the COUNT command of the 7 WRRC U OF Minn Special Report Sixteen 10 program For the SOILS demonstration file the highest class number is 12 see the list of categories in Table 1 What is the HIGHEST CLASS number in the file 0 255 12 The program will now
6. format with this program In addition single bands of a Landsat satellite image in the ERDAS system can be converted to an equivalent EPPL7 format All color and legend information associated with a data file is transfered between the two systems Written in Microsoft Fortran 77 the program is easily adaptable to newer version of data files in either GIS The ERDAS and EPPL7 Systems The ERDAS Earth Resources Data Analysis System package combines the processing of satellite imagery with the analytic tools of a geographic information system This cell based system commonly handles classified data with categories numbered from 0 to 255 where 0 represents offsite or background areas Software procedures allow the user to rectify a satellite image to a map base collect spectral signatures of land cover identified on the image create a classified GIS map of the satellite image overlay additional GIS files for identification of spatially congruent activities e g forested land cover on sandy soils with 5 to 10 percent slopes that are owned by the Federal Government select smaller windows from a larger file for subsequent analysis change the cell size resolution of the data to match other GIS maps and print the files as maps for analysis or publication Although the software runs on a standard IBM PC AT computer additional hardware of a specialized nature including a math coprocessor high resolution monitor image pr
7. race religion color sex national origin handicap age or veteran status A PROGRAM TO EXCHANGE ERDAS AND EPPL7 DATA FILES ecial Report 16 Kevin L Anderson Bradley W Scheer GEOGRAPHY DEPARTMENT UNIVERSITY OF MINNESOTA WATER RESOURCES RESEARCH CENTER UNIVERSITY OF MINNESOTA ST PAUL MN 55108 JUNE 1987 A PROGRAM TO EXCHANGE ERDAS AND EPPL7 DATA FILES Kevin L Anderson Bradley W Scheer ABSTRACT This report is the documentation and user manual for a FORTRAN 77 computer program to convert geographic information system GIS files and satellite data between ERDAS image analysis system and EPPL7 GIS file formats This program expands the data capture ability of the EPPL7 GIS and allows users to take advantage of the analytical techniques of both systems when using an IBM PC AT or compatible computer equipped with an Enhanced or Professional Graphics Adapter and appropriate ERDAS hardware and software Hardware Software Requirements IBM PC XT AT or compatible computer 256 Kilobytes memory monochrome or color display adapter two floppy disk drives or combination of a hard and floppy disk drive PC MS DOS 3 10 or later Disclaimer The authors of this program and the names of individuals listed as contact persons at the University of Minnesota are not responsible for the consequences or damages that may result from an incorrect or unsupervised use of this program including the inadvertent modifi
8. ack to the main menu ERDAS EPPL7 Conversion Program 11 An ERDAS Trailer file can still be created without the existence of either or both of the EPPL7 Color Table and Legend files Not all EPPL7 files are required to have legend or color information If either file does not exist the ERDAS Trailer file is created using fabricated values all black colors or blank legend names A frequency count of class values is still written to the Trailer file regardless of the existence of either EPPL7 file For example if neither file exists the following messages will be displayed Writing COLOR TABLE to the Trailer File Oops find Eppl7 Color File Writing Dummy Version to the Trailer File Writing HISTOGRAM to the Trailer File Writing LEGEND to the Trailer File Oops Can t find Eppl7 Legend File Writing Dummy Version to the Trailer File A missing file message may only indicate that the Color Table or Legend file exist on a different floppy disk or subdirectory than the GIS files If this is the case the currrent version of the EPPERD program requires the user to rerun the entire conversion process after making the color table or legend files available The EPPERD program does not have the option to convert or create just the trailer file LEAVING THE PROGRAM Option 3 of the main menu is used to exit the program Conversion Type _ 1 From ERDAS to EPPL7 2 Fr
9. cation or loss of data or the loss of entire files We are also not responsible for any misuse or misinterpretation of the data used with this Program We cannot guarantee the program or documentation to be entirely error free The program was tested on an IBM AT with 512 kilobytes of memory IBM Monochrome and Professional Graphics Displays and no memory resident programs such as SideKick etc we cannot guarantee that your particular hardwarc softwarc configuration will not interfere with the proper operation of the software The current version of the EPPL ERDAS conversion program described in this document does not provide for backup copies or protection of existing files that are overwritten by an operation of this program The user of this program is expected to provide the necessary file protection and backup of their data A PROGRAM TO EXCHANGE ERDAS AND EPPL7 DATA FILES Kevin L Anderson Bradley W Scheer INTRODUCTION This utility program converts data files between the ERDAS EPPL7 geographic information systems GIS The particular advantages of both cell based systems can be fully exploited with this package The program is menu driven allowing the user to easily step through the conversion process Data packed in 4 and 8 bit ERDAS formats are currently supported as well as files with up to 10 000 columns of data in each row Due to their incompatible nature 16 bit ERDAS data files cannot be converted to EPPL7
10. e The EPPL7 Color Table and Legend files are assumed to have the same name as the EPP file except for a change in extensions If the user responds with yes the program creates the EPPL7 files Do you want to convert the ERDAS Trailer TRL file Y or Reading Histogram Creating LEGEND file Creating COLOR TABLE file After the successful conversion of the ERDAS Trailer File the program returns to the main menu If the user responds to the request with no N the program goes immediately back to the main menu ERDAS EPPL7 Conversion Program 9 OPTION 2 CONVERSION TO ERDAS Option 2 on the main menu selects the conversion of an EPPL7 GIS file to the ERDAS system Enter a 1 2 or 3 2 The program prompts the user for the names of the data files to convert Enter a file name for EPPL7 EPP file soils Enter a file name for an ERDAS GIS file soils The two filenames do not necessarily have to be the same although similarity can help someone trying to trace the origin of a file The user also does not need to enter an extension for each file The program automatically assumes a EPP extension for EPPL7 file and a GIS extension for an ERDAS GIS file If you wish to convert EPPL7 file into a satellite image file with one band on the ERDAS system you must enter both the file name and the LAN file extension e g mobbay lan
11. e EPPL7 program in response to the DOS prompt ERDAS EPPL7 Conversion Program 5 USING THE CONVERSION PROGRAM Operation of the EPPERD conversion Program is simple In the examples that follow Bold Statements represent messages or requests Presented by the Program and reply are responses provided by the user The ERDAS GIS file SOILS GIS is used in this demonstration That file uses 13 categories including the offsite category to map soils of the Mobile Bay area by their textural class TABLE 1 CATEGORIES IN THE ERDAS SOILS DEMONSTRATION FILE LEVEL 0 IS THE OFFSITE CATEGORY Level Legend 1 Gravelly Loamy 2 Fine Sandy Laomy 3 Coarse Sandy Loamy 4 Coarse Loamy 5 Clayey 6 Clayey Mixed 7 Loamy 8 Fine Loamy 9 Silt Loamy 10 Silt Sandy 11 Sandy 12 Mobile Bay amp Gulf of Mexico The SOILS GIS file is part of the standard ERDAS installation package and not included with the EPPERD program In this documentation we also refer to a Landsat image of the Mobile Bay area MOBBAY LAN which is included with the ERDAS system as an example of a satellite image that might be used with a GIS To help the user understand the conversion Process the following description of Program options has been divided by task We will begin by describing how to Start the program and receive the main menu After that each menu option will be discussed Separately The conversion of ERDAS GIS and Landsat image files to the EPPL7 wil
12. e for the consequences or damages that may result from an incorrect or unsupervised use of this program including the inadvertent modification or loss of data or the loss of entire files We are also not responsible for any misuse or misinterpretation of the data used with this program We cannot guarantee the program or documentation to be entirely error free The program was tested on an IBM AT with 512 kilobytes of memory IBM Monochrome and Professional Graphics Displays and no memory resident programs such as SideKick etc we cannot guarantee that your particular hardware software configuration will not interfere with the proper operation of the software The current version of the EPPL ERDAS conversion Program described in this document does not provide for backup copies or protection of existing files that are overwritten by an operation of this program The user of this program is expected to provide the necessary file protection and backup of their data
13. f those machines are separate from the computer that contain the ERDAS software If a floppy disk must be used install the program on a disk that has been formatted to contain a copy of the operating system using the DOS FORMAT command with the S option Because of the potentially large size of many GIS or Landsat files we do not recommend this type of operation unless high density 720 Kb 1 2 Mb or 1 4 Mb floppy disks are available Installation on the ERDAS computer With the current implementation of the ERDAS software Revision 7 2 the EPPERD program should be installed in the same subdirectory as the ERDAS programs On our IBM AT that subdirectory is C ERDAS72 PROGS To copy the EPPERD program to this subdirectory use the DOS command as follows COPY A EPPERD EXE C ERDAS72 PROGS V The EPPERD program can be executed from the ERDAS menu system by typing its name in response to the ERD gt prompt Installation on the EPPL7 computer Please ignore the following if the EPPL7 and ERDAS computers are the same The EPPERD program should be installed on the same subdirectory as the EPPL7 program On our particular IBM AT this subdirectory is C EPPL7 To copy the EPPERD program to this subdirectory use the DOS COPY command as follows COPY A EPPERD EXE C EPPL7 V Substitute your particular subdirectory name for the C EPPL7 used in this example The EPPERD program can now be executed outside th
14. l be discussed first followed by the conversion of data files from EPPL7 to the ERDAS System Although we use the same SOILS file to demonstrate both options the user will rarely need to convert a file from one System to another and then back again WRRC U OF Minn Special Report Sixteen 6 STARTING THE PROGRAM The conversion utility is started by simply typing epperd or in a subdirectory assigned by the DOS PATH command The user needs only to type EPPERD in response to the ERD gt Prompt When used on a computer with EPPL7 the conversion program executes outside the EPPL7 package When the EPPERD Program is loaded the following message appears nL Asteeeeaeesassessassocessescccesssonceessssseccesonceses EPPL7 ERDAS Data File Conversion Program Copyright C ss hee Department of Geography 2 University of Minnesota hes Version 2 33 July 1987 ae se ss Following this message the program will display its standard menu and request a conversion Option Conversion Type 1 From ERDAS to EPPL7 2 From EPPL7 to ERDAS 3 Exit Program Enter a 1 2 or 3 ana 1 2 or 3 is entered the program will display an error message for an incorrect option and display the menu second time After each file Conversion the program will once again display this menu ERDAS EPPL7 Conversion Program 7 OPTION 1 CONVERSION TO EPPL7 Option on the main menu selects the conversi
15. ocessing board nine track magnetic tape drive and color printer is also necessary Versions of the ERDAS software also exist for DEC VAX Prime and Data General computers which we currently do not support with this conversion program The EPPL7 Environmental Planning and Programming Language Version 7 software provides a complete set of procedures for a cell based GIS The package requires only a vanilla IBM PC two floppy disk drives color display adapter and 256 kilobytes of memory Although the standard color display adapter CGA with four colors is supported an enhanced color adapter EGA with 16 simultaneous colors out of 64 or a professional color adapter PGA with 256 simultaneous colors out of 4096 is recommended Categories in an EPPLJ file are numbered from 0 to 255 Separate text files contain the legend or color sequence in intensity of red blue and green colors for each class of a map WRRC U OF Minn Special Report Sixteen 4 SOFTWARE INSTALLATION The distribution disk for the conversion program contains a single program EPPERD EXE Although the program will execute from a floppy disk the software operates faster if installed on a hard disk We recommend installation of the EPPERD program on the ERDAS computer since that system requires a hard disk for its operation We grant permission for additional copies of this program to reside on each computer that contains the EPPL7 package i
16. om EPPL7 to ERDAS 3 Exit Program Enter a 1 2 or 3 3 The program returns the user to the default DOS prompt e g C gt ERROR MESSAGES This EPPERD program has been designed to catch errors without forcing a Premature end of the program For user responses e g conversion option file names band numbers yes no questions etc an incorrect response usually leads to an error message followed by a repeat of the question Trouble encountered during the processing of files e g read errors incorrect data formats etc usually results in cancellation of the requested conversion WRRC U OF Minn Special Report Sixteen 12 Problems with the EPPERD file conversion program should be reported to the contact persons listed below Please include a printed copy of the screen display plus a description of your data files and equipment with your correspondence to help us diagnose the problem REFERENCES The following persons may be contacted for information on the program and to report specific problems with the software Dr Dwight Brown or Dr Philip Gersmehl Department of Geography University of Minnesota Twin Cities 414 Social Science Building 267 19th Avenue South Minneapolis Minnesota 55455 Please refer to Special Report No 16 in your correspondence Disclaimer The authors of this program and the names of individuals listed as contact persons at the University of Minnesota are not responsibl
17. on of ERDAS GIS or Landsat file to a comparable EPPL7 file Enter a 1 2 or 3 1 The program will now prompt the user for names of the data files to convert Enter a file name for an ERDAS GIS file soils Enter a file name for an EPPL7 EPP file Soils GIS extension for an ERDAS GIS file and EPP extension for an EPPL7 filc If you wish to convert a single band of a satellite image on the ERDAS system you must enter both the file name and the LAN file extension e g mobbay lan for the ERDAS file If either file cannot be found the Program will request a different filename from the user Make sure that the Proper disk drive is specified for each file You do not need to enter the disk drive letter or subdirectory designation if they are the same as the default drive specified in the DOS prompt After the files have been located the program will read the header record of the ERDAS file to obtain the number of lines and columns packing format and the number of bands in the data file If more than one band is present in the file ie the ERDAS file represents a Landsat image the Program will request a number for the band to convert This ERDAS file contains 4 bands Which Band do you want to Copy The user should select a band for the conversion For example Which Band do you want to Copy 3 will convert the third image band out of four When a Landsat file is converted to an EPPL7 GIS
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