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Multipath Assessment Tool

1. The multipath amplitude and residuals are normalized with respect to the reference correlation func tion D U desired signal power relative to undesired signal power in units of decibels dB can be calculated from the amplitude of the multipath signal 20 log amplitude of multipath signal 56 Multipath Assessment Tool MAT User Manual Rev 2 NovAtel Format Data Logs Table 6 MEDLL Status Bits Appendix B Position Field Description 0x00000001 Sync bit 1 if MEDLL channels in sync 0 if not in sync Sync bit is set to 1 if the different hardware channels use to track the same PRN are aligned 0x00000002 Phase processing When phase processing is on the bit is 1 MEDLL will determine the phase of the multipath signal If phase processing is set to0 MEDLL will not process the phase of the multipath signal 0x000007C Type of MEDLL will always be 0 for MAT 0x00000380 Number of signals will always be 1 for MAT Other bits Reserved Set to 0 Multipath Assessment Tool MAT User Manual Rev 2 57 Appendix B NovAtel Format Data Logs B 4 4 POSA B Computed Position This log will contain the last valid position and time calculated referenced to the antenna phase centre The position is in geographic coordinates in degrees based on your specified datum default is WGS84 The height is referenced to mean sea level The receiver time is in GPS weeks and seconds int
2. GPSCard Datum ID NAME DATUM DESCRIPTION ELLIPSOID Number 1 ADIND 162 12 206 Adindan Ethiopia Mali Senegal Clarke 1880 amp Sudan 2 ARC50 143 90 294 ARC 1950 SW amp SE Africa Clarke 1880 3 ARC60 160 8 300 ARC 1960 Kenya Tanzania Clarke 1880 4 AGD66 133 48 148 Australian Geodetic Datum 1966 Australian National 5 AGD84 134 48 149 Australian Geodetic Datum 1984 Australian National 6 BUKIT 384 664 48 Bukit Rimpah Indonesia Bessel 1841 7 ASTRO 104 129 239 Camp Area Astro Antarctica International 1924 8 CHATM 175 38 113 Chatum 1971 New Zealand International 1924 9 CARTH 263 6 431 Carthage Tunisia Clarke 1880 10 CAPE 136 108 292 CAPE South Africa Clarke 1880 11 DJAKA 377 681 50 Djakarta Indonesia Bessel 1841 12 EGYPT 130 110 13 Old Egyptian Helmert 1906 13 ED50 87 98 121 European 1950 International 1924 14 ED79 86 98 119 European 1979 International 1924 15 GUNSG 403 684 41 G Segara Kalimantan Bessel 1841 Indonesia 16 GE049 84 22 209 Geodetic Datum 1949 New International Zealand 1924 17 GRB36 375 111 431 Great Britain 1936 Ordinance Airy 1830 Survey 18 GUAM 100 248 259 Guam 1963 Guam Island Clarke 1866 62 Multipath Assessment Tool MAT User Manual Rev 2 NovAtel Format Data Logs Appendix B GPSCard Datum ID NAME DATUM DESCRIPTION ELLIPSOID Number 19 HAWAII 89 279 18
3. On How to Use Help About a The devices in Table 1 represents either the name of a previously opened file or a connection to a WAAS type receiver in MAT The last five device configuration names are displayed Multipath Assessment Tool MAT User Manual Rev 2 Chapter 3 MAT Menus Overview 3 2 3 3 Window Menu The MAT Window menu allows automatic arrangement of all open windows inside MAT for easier viewing Tile arranges the open windows in smaller sizes to fit next to each other within the MAT window Cascade causes any open windows to overlap so that the title bars are visible The Arrange Icons menu item arranges all the windows that have been minimized License Menu The MAT License menu enables you to transfer a license to your computer or set up a retail version of the software 3 3 1 Transfer License From This Computer MAT will allow you to transfer a license from one computer to another To transfer a license you need one computer to have a valid retail license Insert a blank floppy disk into the non licensed computer and select Transfer License To This Computer from the License menu The computer will create a license file on the floppy disk Leave MAT running Go to the computer with the valid license insert the floppy disk and select Transfer License From This Computer The computer will transfer information to the floppy disk and the MAT program will quit automatically The final
4. 4 4 El sal Ga GA SL OL o Ed W I Default The Freeze check box when selected stops the polar plot from using any new data and therefore the plot stays unchanged When the Draw check box is selected it stops the polar plot from changing however it is still accepting new data En co E jallallalta 5 The PRN checkboxes along the right side of each plot allow you to add and remove satellite PRNs from the plot Click once on the colours representing a range of values to change the colour A standard Windows colour dialog appears Select a colour or define a custom colour and press the OK button The Reset Plot button in the plot window allows you to reset the plot Statistics L E The Statistics window reports the mean the standard deviation and the minimum D U values It also reports the mean standard deviation and maximum values for the estimated pseudorange error For an explanation of D U and pseudorange error please see Page 41 Multipath Assessment Tool MAT User Manual Rev 2 View Menu Chapter 5 fey Statistics Window DU Mean DU std Ps Mar PstMean Psr Std Sanple 175 27 5 1 9 C5 0 4 Az 3to 300 EE 3to90 175 303 48 1 9 C4 0 4 1684 Az Dto 360 EL 0to90 110 29 6 5 2 41 C4 0 4 1967 z to1El Uto YL 11 U 3 b 5 2 41 LA UA 13bf Delete Selected Add Each row displays statistics for a user defined range of azimuth and elevation Right click anywhere in t
5. If you select Capture Once both buttons appear grey until the capture is finished and then the screen capture dialog may be used again To close the Screen Capture dialog click on the Close button Screen Capture JEVEM Eanes Gy FAPublications in progress Multipath S w 95 AVEO EE AU SEVT SIDEC 36 Multipath Assessment Tool MAT User Manual Rev 2 IND Radio Frequency RF And Multipath A 1 Overview The influence on radio wave propagation depends on the frequency and propagation mediums through which the RF signal travels UHF signals such as GPS are highly susceptible to reflections because of the short wavelengths at the L1 channel As GPS is a radio navigation ranging system the direct path signal is of primary interest Any propagation delays or multipath reception causes biases to the ranging measurements that cannot be differenced by traditional DGPS single differencing techniques Multipath is the greatest source of errors to a system operating in single differencing mode see Figure 2 Careful site selection and the GPS model 600 Pinwheel Technology antenna or good patch antenna design combined with a choke ring ground plane are very effective in reducing multipath reception see Figure 3 The role of a correlator is discussed to provide some insight into how multipath influences the correlation function required for satellite tracking and ranging MEDLL is a multi correlator array technology whereby a mult
6. NovAtel DISCLAIMS AND EXCLUDES ALL OTHER WARRANTIES IN NO EVENT WILL NovAtel s LIABILITY OF ANY KIND INCLUDE ANY SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES INCLUDING LOST PROFITS EVEN IF NovAtel HAS KNOWLEDGE OF THE POTENTIAL LOSS OR DAMAGE b NovAtel will not be liable for any loss or damage caused by delay in furnishing the software or any other performance under this Agreement c NovAtel s entire liability and your exclusive remedies for our liability of any kind including liability for negligence for the software covered by this Agreement and all other performance or non performance by NovAtel under or related to this Agreement are to the remedies specified by this Agreement This Agreement is governed by the laws of the Province of Alberta Canada Each of the parties hereto irrevocably attorns to the jurisdiction of the courts of the Province of Alberta Multipath Assessment Tool MAT User Manual Rev 2 6 Customer Service If you require customer service please provide the following information along with a detailed description of the problem when you call or write Date Purchased Purchased from User name Title Company Address City Prov State Zip Postal Code Country Phone Fax GPSCard interface Computer type Operating Shell Other interface used Please provide a complete description of any problems you may be experiencing or the nature of
7. Structure DOPA week sec gdop pdop htdop hdop tdop sats prns Tax CR LF Field re Data Description Example ype 1 DOPA Log header DOPA 2 week GPS week number 637 3 sec GPS seconds into the week 512473 00 4 gdop Geometric dilution of precision assumes 3 D position 2 9644 and receiver clock offset all 4 parameters are unknown 5 pdop Position dilution of precision assumes 3 D position is 2 5639 unknown and receiver clock offset is known 6 htdop Horizontal position and time dilution of precision 2 0200 H hdop Horizontal dilution of precision 1 3662 8 tdop Time dilution of precision assumes 3 D position is 1 4880 known and only receiver clock offset is unknown 9 sats Number of satellites used in position solution 0 12 6 See the notes above 10 prns PRN list of SV PRNs tracking 1 32 null field until 18 6 11 2 16 first position solution available 19 variable XX Checksum 29 variable CR LF Sentence terminator CR LF Example DOPA 637 512473 00 2 9644 2 5639 2 0200 1 3662 1 4880 6 18 6 11 2 16 19 29 CR LF Multipath Assessment Tool MAT User Manual Rev 2 45 Appendix B NovAtel Format Data Logs DOPB Format Message ID 07 Message byte count 68 sats 4 1 3 0 Sync char header Checksum 1 char 3 Message ID 4 integer 4 Message byte count 4 integer bytes 8 2 Week number 4 integer weeks 12 3 Seconds of week 8 double seconds 16 4 gdop 8
8. Structure TMIA week seconds offset offset std utc offset cm status Xx CR LF Field Data Description Example 1 TMIA Log header TMIA 2 week GPS week number 794 3 seconds GPS seconds into the week at the epoch coincident with 414634 99999996 the 1PPS output strobe receiver time 6 4 offset Receiver clock offset in seconds A positive offset 0 000000078 implies that the receiver clock is ahead of GPS Time To derive GPS time use the following formula GPS time receiver time offset 5 offset std Standard deviation of receiver clock offset in seconds 0 00000002 1 6 utc offset This field represents the offset of GPS time from UTC 9 999999998 time computed using almanac parameters To reconstruct UTC time algebraically subtract this correction from field 3 above GPS seconds UTC time GPS time utc offset 7 cm status Receiver Clock Model Status where 0 is valid and values 0 from 20 to 1 imply that the model is in the process of stabilization 8 xx Checksum 57 9 CR LF Sentence terminator CR LF Example TM1A 794 414634 999999966 0 000000078 0 00000002 1 9 999999998 0 57 CR LF Multipath Assessment Tool MAT User Manual Rev 2 69 Appendix B NovAtel Format Data Logs TM1B Format Message ID 03 Message byte count 52 Field Data Bytes Format Units Offset 1 Sync 3 char 0 header Checksum 1 char 3 Message ID 4 integer 4
9. 0 00418267 residual correlator 1 54 Multipath Assessment Tool MAT User Manual Rev 2 NovAtel Format Data Logs Appendix B Repeated for each correlator 45 12 Quadrature phase Quadrature phase residual value from 0 00730140 residual correlator 12 46 xx Checksum 71 47 CR LF Sentence terminator CR LF Example MPMA 0 27 77 29 6A84 103 1 08154941 0 0173 143 1 0 00645047 0 00160142 0 00164832 0 00078 163 0 0000 1205 0 00083644 0 00240084 0 00214321 0 00079274 0 00032872 0 00084985 0 00000891 0 00196318 0 00418267 0 00443155 0 00665589 0 00580890 0 00078493 0 00101275 0 00468876 0 00449791 0 00126932 0 00140528 0 00004035 0 00730140 71 CR LF Multipath Assessment Tool MAT User Manual Rev 2 55 Appendix B NovAtel Format Data Logs MPMB Format Message ID 95 Message byte count 144 Field Data Bytes Format Units Offset 1 Sync 3 Char 0 header Checksum 1 Char 3 Message ID 4 Integer 4 Message Byte Count 4 Integer bytes 8 2 Week Number 4 Integer weeks 12 3 Seconds of Week 8 Double seconds 16 4 PRN 4 Integer 24 5 Channel Status 4 Integer 28 6 MEDLL Status 4 Integer 32 7 Delay 4 Float C A chips 36 8 Amplitude 4 Float 40 9 Phase 4 Float 44 10 1 in phase residual 4 Float 48 22 12 in phase residual a Float 92 23 1 Quadrature phase 4 Float 96 residual 45 12 Quadrature phase 4 Float 140 residual
10. 1 1988 Supplement to Department of Defence World Geodetic System 1984 Technical Report Part II Parameters Formulas and Graphics for the Practical Application of WGS84 December 1 1987 Table 7 Reference Ellipsoid Constants Airy 1830 AW 6377563 396 299 3249647 0 00334085064038 Modified Airy AM 6377340 189 299 3249647 0 00334085064038 Australian National AN 6378160 0 298 25 0 00335289186924 Bessel 1841 BR 6377397 155 299 1528128 0 00334277318217 Clarke 1866 CC 6378206 4 294 9786982 0 00339007530409 Clarke 1880 CD 6378249 145 293 465 0 00340756137870 Everest India 1830 EA 6377276 345 300 8017 0 00332444929666 Everest Brunei amp EB 6377298 556 300 8017 0 00332444929666 E Malaysia Everest W Malaysia amp ED 6377304 063 300 8017 0 00332444929666 Singapore Geodetic Reference System RF 6378137 0 298 257222101 0 00335281068118 1980 Helmert 1906 HE 6378200 0 298 30 0 00335232986926 Hough 1960 HO 6378270 0 297 00 0 00336700336700 International 1924 IN 6378388 0 297 00 0 00336700336700 South American 1969 SA 6378160 0 298 25 0 00335289186924 World Geodetic System WD 6378135 0 298 26 0 00335277945417 1972 World Geodetic System WE 6378137 0 298 257223563 0 00335281066475 1984 Multipath Assessment Tool MAT User Manual Rev 2 61 Appendix B NovAtel Format Data Logs Table 8 Transformation Parameters Local Geodetic to WGS84
11. Message byte count 4 integer bytes 8 2 Week number 4 integer weeks 12 3 Seconds of week 8 double seconds 16 4 Clock offset 8 double seconds 24 5 StdDev clock offset 8 double seconds 32 6 UTC offset 8 double seconds 40 7 Clock model status 4 integer 0 good 1 to 20 bad 48 70 Multipath Assessment Tool MAT User Manual Rev 2 Appendix C Some Common Unit Conversions Distance 1 metre m 100 centimetres cm 1000 millimetres mm 1 kilometre km 1000 metres m 1 nautical mile 1852 metres 1 international foot 0 3048 metre 1 statute mile 1609 metres 1 US survey foot 0 3048006096 metre Frequency L1 frequency 1575 42 MHz L2 frequency 1227 60 MHz Temperature degrees Celsius 5 9 x degrees Fahrenheit 32 degrees Fahrenheit 9 5 x degrees Celsius 32 Hexadecimal And Binary Equivalents Hexadecimal Binary Hexadecimal Binary 0 0000 8 1000 1 0001 9 1001 2 0010 A 1010 3 0011 B 1011 4 0100 C 1100 5 0101 D 1101 6 0110 E 1110 7 0111 F 1111 Multipath Assessment Tool MAT User Manual Rev 2 71 Appendix C Some Common Unit Conversions GPS Time of Week To Week and Time of Day example 511200 seconds Day 511200 86400 seconds per day 5 916666667 days Hour 0 916666667 x 86400 3600 seconds per hour 22 0000 hours Minute 0 000 x 3600 60 seconds per minute 0 000 minutes Second 0 000 x 60 0 000 seconds Day 5 Thursday 22 hours 0
12. a new file The software will automatically add an extension to the filename in the following form _gpsweek_gpseconds where is an automatically incremented number gpsweek is the GPS week number gpseconds is the number of GPS seconds into the week This will help you to see when a file was created The software will be able to decide in what order to Multipath Assessment Tool MAT User Manual Rev 2 21 Chapter 5 View Menu play files when in playback file mode The MPMB SATB DOPB POSB TM1B and ETSB logs are logged automatically by MAT but you can add logs in the Logging Control section of the Save to File dialog To start a new log click on the Start New Log button Start New Log Type of Tigger Period 1 0 ontime C onnew Offset o o C onchanged C once Start Log V Hold Log Close Select a log from the list choose a trigger and then if the log trigger is ontime enter its period and offset The hold check box is permanently checked for all your log choices This ensures that the UNLOGALL command does not affect those logs in your Logging Control list Click on the Start Log button to add it to the list in the Save to File dialog To remove a log from the list highlight it and press the Unlog Selected Log button The Unlog All In List button removes all the logs in the Logging Control list The Save Every MPM Log field allows you to choose how often you save an MPM log every one to every 1
13. minutes 0 seconds into Friday Calendar Date to GPS Time e g 13 30 hours January 28 2005 Days from January 6 1980 to January 28 2005 6 years x 365 days year 9125 days Add one day for each leap year a year which is divisible by 4 but not by 100 unless it is divisible by 400 every 100 years a leap year is skipped 7 days Days into 2005 28th is not finished 27 days Total days 9159 days Deduct 5 days Jan 1 5 1980 9154 days GPS Week 9154 x 86400 seconds per day 790905600 seconds 604800 sec per week 1307 weeks Seconds into week 6th day 13 5 hrs x 3600 sec hr 48600 seconds GPS time of week Week 1307 48600 second 72 Multipath Assessment Tool MAT User Manual Rev 2 Appendix D Acronyms ASCII American Standard Code for Information Interchange bps Bits per Second BW Bandwidth C A Code Coarse Acquisition Code C Ng Post Correlation Carrier to Noise Ratio in dB Hz dB Decibel DGPS Differential Global Positioning System DOP Dilution Of Precision D U Desired Undesired GDOP Geometric Dilution Of Precision GPS Global Positioning System GUS Ground Uplink Station HDOP Horizontal Dilution Of Precision hex Hexadecimal Hz Hertz MAT Multipath Assessment Tool MEDLL Multipath Estimating Delay Lock Loop MET Multipath Elimination Technology MHz Mega Hertz MPM Multipath Meter OEM Original Equipment Manufacturer PC Personal Computer P Code Precise Code PDOP Position Dilution Of Precision PRN Pse
14. number the issue date of the MAT software and NovAtel s contact information Multipath Assessment Tool MAT User Manual Rev 2 13 Chapter 4 Device Menu 4 1 This menu allows you to open and close a file or serial port that supplies MAT with NovAtel logs Both are referred to as a device in this manual You can also print or exit MAT completely from this menu Open To open a device choose either Device Open Serial or Device Open File from the main menu You can also open a device by selecting a device configuration from the numbered list in the Device menu This list displays the last five devices that have been opened by MAT You can look in the far right of the MAT status bar to see what devices are currently open ae The icon on the left shows that a file device is open while the icon on the right shows that a serial device is open To make an open device an active configuration right click over its icon and choose Select from the options You can also select an active configuration by choosing one of the devices that appear when you select Device Active Config from the main menu 4 1 1 Open Serial When you select Device Open Serial from the menu the Serial Device Settings dialog appears Serial Device Settings EN OK PC Pott Cancel Use hardware handshaking I ale ali Use the down arrow in the PC Port list to select the COM port on your PC that your device is connected to Handshaki
15. precision long 4 32 The long type is a 32 bit integer in the range 2147483647 to 2147483648 Each byte within an int has its own address and the smallest of the addresses is the address of the int The byte at this lowest address contains the eight least significant bits of the double word while the byte at the highest address contains the eight most significant bits Similarly the bits of a double type are stored least significant byte first This is the same data format used by personal computers B 3 Time Conventions All logs report GPS time expressed in GPS weeks and seconds into the week The time reported is not corrected for the local receiver s clock error GPS time is based on an atomic time scale Universal Time Coordinated UTC time is also based on an atomic time scale with an offset of seconds applied to coordinate Universal Time to GPS time GPS time is designated as being coincident with UTC at the start date of January 6 1980 00 hours GMT GPS time does not count leap seconds and therefore an offset exists between UTC and GPS time The GPS week consists of 604800 seconds where 000000 seconds is at Saturday midnight Each week at this time the week number increments by one and the seconds into the week resets to 0 Multipath Assessment Tool MAT User Manual Rev 2 43 Appendix B NovAtel Format Data Logs B 4 Log Descriptions The log references that follow are in alphabetical order For
16. satellite s clock It is in the matching of the individual received C A codes against those generated by the local receiver code generator that the correlator becomes of crucial importance As the name correlator implies it must be able to correlate a match between two PRN codes Unless correlation can be achieved the received signals only appear as random noise Figure 4 Example of C A Code Correlation gt HOE Pie lel ted N x I N I M C A Code Propagation Ranging Delay Pseudorangg V rr Dm FULL Satellite Received Code Locally Generated Code 0 4 Chip Offset Auto correlation match 1 1 Negative pulse represents Positive pulse represents no correlation correlation The GPS receiver measures its distance from each satellite by measuring the time it takes the GPS signal to propagate from the satellite to the receiver antenna The GPS receiver determines its position by means of trilateration of the range measurements of at least four measured satellite ranges The receiver s ability to accurately correlate and phase lock on each PRN code directly influences the accuracy of the receiver s range measurements accuracy which in turn affects the accuracy of the computed position NovAtel s WAAS MEDLL has sixteen parallel channels that can simultaneously Multipath Assessment Tool MAT User Manual Rev 2 Radio Frequency RF And Multipath Appendix A correlate and track up to 16 satellites A 2 1
17. splits the received signals into their direct path and multipath components by determining the amplitude delay and phase angle of each of the signals Further discussion on the correlator and MEDLL technology are provided in A 2 The Role of the GPS Receiver Correlator beginning on Page 38 The MPMB SATB DOPB POSB TM1B and ETSB logs are used by MAT For a description of these logs please see Appendix B beginning on Page 42 1 2 Scope The Multipath Assessment Tool User Manual is a complete installation reference and instructional manual for the MAT software This manual describes the graphical user interface on your PC that is used to collect view and manage logged information as it is output by the Multipath Meter feature from a MEDLL capable receiver see Figure I It can also be used to post process previously collected MEDLL data from the correct logs in order to study the multipath environment Figure 1 Real Time Data Collection lt Reference Description 1 WAAS EGNOS MSAS or a Portable MEDLL receiver with MPM firmware Antenna PC Connection to L1 C A or WAAS MEDLL Connection to COM1 or COM2 22 30 V DC power supply Oo G0 AR O NWN Multipath Assessment Tool MAT User Manual Rev 2 8 Introduction Chapter 1 1 3 Prerequisites The recommended minimum system requirements to run MAT are e A Pentium class PC with 32MB e 6MB of hard disk space for program files e Microsoft Windows NT 2000 98 95 e Micr
18. step is to transfer the license file from the floppy disk to the non licensed computer by following the instructions on the screen 3 3 2 Enable Retail Version Of Software 12 Select Enable Retail Version Of Software from the License menu The Enable Full Version of MAT dialog appears with three fields Computer ID Copy the Computer ID number down and send it to NovAtel s Customer Service department by phone facsimile or e mail See Page 7 for contact information NovAtel Key 1 The first NovAtel key supplied by our Customer Service personnel NovAtel Key 2 The second NovAtel key supplied by our Customer Service personnel Enter the two NovAtel key numbers into the Enable Full Version of MAT dialog and press the OK button The retail version will then be ready to use Multipath Assessment Tool MAT User Manual Rev 2 MAT Menus Overview Chapter 3 3 4 Help Menu The MAT program has been enhanced by the inclusion of a Help system that can be accessed from any dialog If a screen does not include a Help button press the F1 key on your keyboard to bring up the help for that screen You can also click on the Help option in the main menu to bring up the help files The Help contains excerpts from this manual to clarify the contents and function of each screen If you are unfamiliar with using a Windows Help file assistance can be obtained by looking through the How to Use Help option topics The About window reveals the MAT version
19. the binary logs the 32 bit CRC is calculated with all fields in the log filled except for the check sum field which is zero For the ASCII logs the 32 bit CRC is calculated from all fields of the log after the symbol Once the CRC has been calculated the log checksum is calculated in the normal fashion in order to preserve the standard NovAtel log format The GPS seconds into the week value is stored in a number of different ways within the receiver Depending on which log is being output the time may be derived from a different source However all sources of time are interconnected Generally the seconds into the week field is stored as either an integer in milliseconds or a floating point value before being output in the log B 4 1 DOPA B Dilution of Precision 44 The dilution of precision data is calculated using the geometry of only those satellites that are currently being tracked and used in the position solution by the GPSCard and updated once every 60 Therefore the total number of data fields output by the log is variable depending on the number of satellites being tracked Twelve is the maximum number of satellite PRNs contained in the list If insufficient satellites are being tracked to calculate DOP values the last calculated DOP values are output Multipath Assessment Tool MAT User Manual Rev 2 NovAtel Format Data Logs Appendix B DOPA
20. the receiver fills in the stored almanac with ephemeris data from tracked satellites When the Core Computer requests the almanac the receiver provides this stored almanac Once the almanac is received the receiver overwrites its stored alma nac with the real almanac This almanac does not contain data associated with satellites that are already being tracked that have a good ephemeris health and a bad almanac health this is because the ephemeris is generally more up to date SATA Structure SATA week Seconds sol status obs prn azimuth elevation residual reject code prn azimuth elevation residual reject code XX CR LF 1 SATA Log header SATA 2 week GPS week number 637 3 seconds GPS seconds into the week 513902 00 4 sol status Solution status as listed on Page 52 0 5 obs Number of satellite observations with information to follow 7 6 prn Satellite PRN number 1 32 18 7 azimuth Satellite azimuth from user position with respect to True North 168 92 in degrees 66 Multipath Assessment Tool MAT User Manual Rev 2 NovAtel Format Data Logs Appendix B 8 elevation Satellite elevation from user position with respect to the 5 52 horizon in degrees 9 residual Satellite range residual from position solution for each satellite 9 582 in metres 10 reject code Indicates that the range is being used in the solution code 0 or 0 that it was rejecte
21. under International copyright laws Printed in Canada on recycled paper Recyclable so Multipath Assessment Tool MAT User Manual Rev 2 Table of Contents 1 Introduction T3 WC EE 14 What s New geesde a ENEE TEE 2 Installation DV QUICK Stata ai fone ntate See E 2 2 MAT Software Eiles cece e a ia a A ia 3 MAT Menus Overview St Men Op cesa a oops 3 2 Window Menu EE BB le E EE 3 3 1 Transfer License From This Computer 3 3 2 Enable Retail Version Of Software eeeeeeeeeeeeeeee nen 34 Help MOn EE 4 Device Menu Reen RS ET EE Ee D FINE st doske ozone kakao a 4 2 ACUIVE CONG era olas to dit ar ta ir 4 4 Close and Close Alicates 4 5 Print and Print Getup rn anna aa crac A O 5 View Menu A A ee deo na Rika v d Aha a A RS ele EE 5 3 Baelen Le De Lutte EE EE 5 4 Satellite Position ugeet Zeg gend Eed eebe ee tens E Ge 5 5 Multipath MiO ET SO ee Tu EE 5 7 D U Azimuth Elevation Polar Plot DO Stalin 5 9 Capture Contro EE Radio Frequency RF And Multipath NovAtel Format Data Logs Some Common Unit Conversions Acronyms CO D gt o Multipath Assessment Tool MAT User Manual Rev 2 Tables 1 Menu Options 2 25 Ae A eee ee ae 11 2 Channel Tracking Status Bits o eee eee nenene nenene een nn 51 3 Bits 12 14 Correlator Spacing ee eeee eee eee ee eee eee nr cnn 52 4 GPSCard Solution Status 2 20 0 ecccecececceeeceeeeeeeeeeeeeeeeeeeeeeee
22. you collect data in one time zone and then play back the data in another time zone the sun will not be correctly placed on the plot Each satellite that is being tracked and is in good health is represented on the window with a stylized picture at its position The satellite PRN is displayed on the body of the satellite A sun icon represents the position of the sun Below are examples of the type of information that appears in the status bar when you position your mouse over the sun or any of the satellites Multipath Assessment Tool MAT User Manual Rev 2 View Menu Chapter 5 Tx A Rx DI Sun Azimuth 256 6 Elevation 36 1 e Tx A Rx B Satelite Pm 22 Azimuth 319 7 Elevation 16 7 e 5 4 1 Plots Right clicking on a satellite will display a Time Series Plot speed menu Click on this speed menu to bring up the Select Multiple Satellites dialog Average Residuals Standard Deviation of Residuals Azimuth Elevation C No Pseudorange Error Enter Time Length of Plots in Seconds 100 Select Cancel Multipath Assessment Tool MAT User Manual Rev 2 25 Chapter 5 View Menu 26 First choose a plot against time from the Select Parameters list You can choose extra satellites to include in the plot from the Select Satellites list Hold down the lt Ctrl gt key select individual PRNs with your mouse and release the lt Ctrl gt key If you want to select all the satellites or all the satellites you want are together in the l
23. 0 MPM logs arrive once every second for every satellite Tracking 12 satellites means logging 12 MPM logs per second This option is to help reduce file size bx It is recommended that you set up the logging control window to create a new file at least every 24 hours When you have added all the logs you require press the Start Recording button in the File IO section of the dialog A green light appears to show you that recording is in progress You can stop the recording at any time by pressing the Stop Recording button 22 Multipath Assessment Tool MAT User Manual Rev 2 View Menu Chapter 5 p Save to File iof E File IO Enter Filename LA FH jue opiate ura Browse V New file every 5 0 MB Stop Recording T New file every fio Min i gt Logging Control FRAMA ontime 1 0 hold _ StetNemlog RGEA onchanged hold TM1 ontime 1 0 hold Unlog Selected Log Unlog All In List Save every y MEM Log Not Recording Size 0 MB Time 0 hours If you start recording and the target file already exists the following message will appear Save To File Message EN File D GUI MPM june6 gpsolution multipath gps Already Exists EE sa C MAT uses a strict file naming convention to keep track of multiple files If you choose an extension other than GPS MAT will warn you and change it to GPS Select Overwrite to overwrite the previously recorded file Appen
24. 0 1 1305229E 0 SALMA 6 7 52020E 003 405504 41 2 2718 9E 000 1 67080754E 000 2 7106396E l SALMA 9 1 03030E 002 405504 41 7 9546E 009 1 4575042E 000 5 91976893E 001 3 04915720E ALMA 10 4 121 30E 003 405504 41 7 9660E 009 2 74851869E 000 4 5729930E 002 1 99736562E SALMA 11 2 41661E 003 405504 41 0 2746E 009 1 67065330E 000 3 0507436E 000 3 99400510E SALMA 13 2 73609E 003 405504 41 7 9775E 009 2 4070G05E 000 4 6708067E 001 3 0G659705E SALMA 15 7 79295E 003 405504 41 7 7032E 009 1 76756269E 000 1 51526780E 000 2 003260 0E SALMA 16 5 06210E 003 405504 41 7 9432E 009 2 00057779E 000 4 20617832E 001 1 37707540E SALMA 171 18400E 002 405504 41 7 6803E 009 1 60673313E 000 2 95661764E 000 2 93526250E 5 3 Logging Control 5 The Logging Control window allows you to browse for a file and record all logs output by the receiver The length of time that the file has been recording and the file size are indicated in the Save to File dialog s status bar The resultant file is the type of file that can be used in playback mode see Page 15 for more information on playback mode You can decide if the file is generated according to an elapsed amount of time or the amount of disk space used Do this by clicking in one of the New File Every checkboxes and then enter the time or disk space specifics for your application If both are checked the condition that is met first is used to decide when to start
25. 0 18 Antenna 1 Secondary O Primary 40000 19 Grouping 1 Grouped O Not grouped 80000 20 Frequency 142 041 100000 21 Codetype O C A 2 P codeless 200000 2 1P 3Z Reserved 400000 23 Formarderrorcorrection 1 FEC enabled 0 noFEC 800000 24 Reserved Setto0 29 30 External range 1 xt range 0 nt range 31 Channel assignment 1 Forced 0 Automatic 1 GEO will never be set for MEDLL channels 0 11 2 Antenna will always be primary 3 MEDLL channels 12 15 will be 1 and MEDLL channels 0 11 will be O 4 When phase parity and code lock have been established the channel has reached steady state tracking in state 4 5 See Table 3 Bits 12 14 Correlator Spacing on Page 52 Multipath Assessment Tool MAT User Manual Rev 2 51 Appendix B NovAtel Format Data Logs Table 3 Bits 12 14 Correlator Spacing State Description 0 Unknown this only appears in versions of software previous to x 4x which didn t use this field 1 Standard correlator spacing 1 chip 2 Narrow Correlator 3 MET uses Early Late Slope Technique to improve Narrow Correlator performance in reducing errors due to multipath 4 Reserved 5 MEDLL decomposes the incoming signal into direct path and reflected path components to reduce errors due to multipath Higher numbers are reserved for future use Table 4 GPSCard Solution Status Value Description 0 Solution computed 1 Insufficient observatio
26. 0 3 seconds GPS seconds into the week 332087 00 receiver time not corrected for clock error CLOCKADJUST enabled 4 sol status Solution status see Page 52 0 5 obs Number of observations to follow 24 6 prn Satellite PRN number 1 32 7 channel 0 3 Multipath Assessment Tool MAT User Manual Rev 2 47 Appendix B 48 NovAtel Format Data Logs 7 ch tr status Hexadecimal number indicating 00082E04 channel tracking status see Page 51 8 dopp Instantaneous carrier Doppler 613 5 frequency Hz 9 C No Carrier to noise density ratio dB 54 682 Hz 10 residual Residual from position filter m 27 617 11 locktime Number of seconds of continuous 12301 4 tracking no cycle slips 12 psr Pseudorange measurement m 20257359 5 7 13 reject code Indicates whether the range is 0 valid code 0 or not see Page 53 14 21 next observation 94 101 last observation 102 xx Checksum 19 103 CR LF Sentence terminator CR LF a Satellite PRN 0 if the channel is idle Multipath Assessment Tool MAT User Manual Rev 2 NovAtel Format Data Logs Appendix B Example carriage returns have been added between observations for clarity SETSA 850 332087 00 0 24 7 00082E04 613 5 54 682 27 617 12301 4 20257359 57 0 7 00582E0B 478 1 46 388 0 000 11892 0 20257351 96 13 5 00082E14 3311 2 35 915 1 037 1224 4 24412632 47 0 5 00582E1B 2580 4 39 56
27. 16 Multipath Assessment Tool MAT User Manual Rev 2 49 Appendix B NovAtel Format Data Logs 4 Solution status 4 integer See Page 24 52 5 No of channels 4 integer number of 28 channelsin receiver 6 PRN number chan 0 4 integer 32 7 Channel tracking status 4 integer See Page 36 51 8 Doppler 8 double Hz 40 9 C No db Hz 8 double db Hz 48 10 Residual 8 double metres 56 11 Locktime 8 double seconds 64 12 Pseudorange 8 double metres 72 13 Rejection code 4 integer See Page 80 53 14 Offset 32 chan x 52 where chan varies from 0 highest channel number 50 Multipath Assessment Tool MAT User Manual Rev 2 NovAtel Format Data Logs Appendix B Table 2 Channel Tracking Status Bits N7 N6 N5 N4 N3 N 2 N1 lt lt Nibble Number 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 1110 9 8 7 6 5 4 3 Bit Description Range Values Hex Isb 9 1 1 Trackingstate 0 1 Seebelow 2 2 4 3 8 4 10 5 0 n 0 first n ast 20 6 Channel number ndependsonGPSCardmodel 40 H 80 8 100 9 Phaselock flag 1 Lock O Not locked 200 10 Parity knownflag 1 Known 0 Not known 400 1 Codelockedflag 14 ock O Notlocked 800 Y 1000 B Correlatorspacingtype 0 7 SeetheCorrelator 2000 Mi Spacing Table 4000 Bj O PS 3 Reserved 8000 16 Satellitesystem FReserved 4 7Reserved 10000 U JEE 2000
28. 27 Clarke 1866 40 CARIBB 7 152 178 N American Caribbean Clarke 1866 41 MEXICO 12 130 190 N American Mexico Clarke 1866 42 CAMER 0 125 194 N American Central America Clarke 1866 43 MINNA 92 93 122 Nigeria Minna Clarke 1880 44 OMAN 346 1 224 Oman Clarke 1880 45 PUERTO 11 72 101 Puerto Rica and Virgin Islands Clarke 1866 46 QORNO 164 138 189 Oornog South Greenland International 1924 47 ROME 255 65 9 Rome 1940 Sardinia Island International 1924 48 CHUA 134 229 29 South American Chua Astro International Paraguay 1924 49 SAM56 288 175 376 South American Provisional International 1956 1924 50 SAM69 57 1 41 South American 1969 S American 1969 51 CAMPO 148 136 90 S American Campo Inchauspe International Argentina 1924 52 SACOR 206 172 6 South American Corrego Alegre International Brazil 1924 53 YACAR 155 171 37 South American Yacare International Uruguay 1924 54 TANAN 189 242 91 Tananarive Observatory 1925 International Madagascar 1924 64 Multipath Assessment Tool MAT User Manual Rev 2 NovAtel Format Data Logs Appendix B GPSCard Datum ID NAME DATUM DESCRIPTION ELLIPSOID Number 55 TIMBA 689 691 46 Timbalai Brunei and East Everest EB Malaysia 1948 56 TOKYO 128 481 664 Tokyo Japan Korea and Bessel 1841 Okinawa 57 TRIST 632 438 609 Tristan Astro 1968 Tristan du International Cunha 1924 58 VITI 51 391 36 Viti Levu 191
29. 3 0 000 1186 7 24412629 40 13 9 00082E24 1183 1 53 294 29 857 7283 8 21498303 67 0 9 00582E2B 921 9 44 422 0 000 7250 2 21498297 13 13 2 00082E34 2405 2 50 824 20 985 19223 6 22047005 47 0 2 00582E3B 1874 1 41 918 0 000 19186 7 22046999 44 13 4 00082E44 3302 8 47 287 7 522 3648 1 22696783 36 0 4 00582E4B 2573 6 37 341 0 000 3191 2 22696778 15 13 14 00082E54 2132 7 41 786 22 388 541 3 25117182 07 0 14 00582E5B 1661 7 33 903 0 000 500 7 25117179 63 13 26 00082E64 3004 3 43 223 2 928 14536 2 25074382 19 0 26 00582E6B 2340 9 33 019 0 000 14491 7 25074378 01 13 15 00082E74 3037 7 43 669 0 508 12011 5 24104788 88 0 15 00582E7B 2367 0 34 765 0 000 11842 4 24104781 53 13 24 00082E84 3814 0 37 081 7 511 95 7 25360032 49 0 24 00582E8B 2972 0 24 148 0 000 5 2 25360030 13 13 28 00082A90 9800 9 0 000 0 000 0 0 0 00 9 28 00382A90 7637 0 0 000 0 000 0 0 0 00 9 3 000822A0 3328 3 0 000 0 000 0 0 0 00 9 3 005828A0 2593 5 0 000 0 000 0 0 0 00 9 27 000822B0 3851 7 0 000 0 000 0 0 0 00 9 27 005828B0 3001 7 0 000 0 000 0 0 0 00 9 41 CR LF ETSB Format Message ID 48 Message byte count 32 n 52 where n is number of channels in receiver Field Data Bytes Format Units Offset 1 Sync 3 char 0 header Checksum 1 char 3 Message ID 4 integer 4 Message byte count 4 integer bytes 8 2 Week number 4 integer weeks 12 3 Time of week 8 double seconds
30. 3 Hawaiian Hawaii Old International 1924 20 KAUAI 45 290 172 Hawaiian Kauai Old International 1924 21 MAUI 65 290 190 Hawaiian Maui Old International 1924 22 OAHU 56 284 181 Hawaiian Oahu Old International 1924 23 HERAT 333 222 114 Herat North Afghanistan International 1924 24 HJORS 73 46 86 Hjorsey 1955 Iceland International 1924 25 HONGK 156 271 189 Hong Kong 1963 International 1924 26 HUTZU 634 549 201 Hu Tzu Shan Taiwan International 1924 27 INDIA 289 734 257 Indian India Nepal Bangladesh Everest EA 28 IRE65 506 122 611 Ireland 1965 Modified Airy 29 KERTA 11 851 5 Kertau 1948 West Malaysia and Everest ED Singapore 30 KANDA 97 787 86 Kandawala Sri Lanka Everest EA 31 LIBER 90 40 88 Liberia 1964 Clarke 1880 32 LUZON 133 771 51 Luzon Philippines excluding Clarke 1866 Mindanoa Is 33 MINDA 133 70 72 Mindanoa Island Clarke 1866 34 MERCH 31 146 47 Merchich Morocco Clarke 1880 35 NAHR 231 196 482 Nahrwan Saudi Arabia Clarke 1880 36 NAD83 0 0 0 N American 1983 Includes GRS 80 Areas 37 42 Multipath Assessment Tool MAT User Manual Rev 2 63 Appendix B NovAtel Format Data Logs GPSCard Datum ID NAME DATUM DESCRIPTION ELLIPSOID Number 37 CANADA 10 158 187 N American Canada 1927 Clarke 1866 38 ALASKA 5 135 172 N American Alaska 1927 Clarke 1866 39 NAD27 8 160 176 N American Conus 19
31. 6 Fiji Islands Clarke 1880 59 WAK60 101 52 39 Wake Eniwetok Marshall Hough 1960 Islands 60 WGS72 0 0 4 5 World Geodetic System 72 WGS 72 61 WGS84 0 0 0 World Geodetic System 84 WGS 84 62 ZANDE 265 120 358 Zanderidj Surinam International 1924 63 USER 0 0 0 User Defined Datum Defaults User Default user datum is WGS84 The POSA B log reports the Datum used according to the GPSCard Datum ID column Multipath Assessment Tool MAT User Manual Rev 2 65 Appendix B NovAtel Format Data Logs B 4 5 SATA B Satellite Specific Data This log provides satellite specific data for satellites actually being tracked The record length is variable and depends on the number of satellites Each satellite being tracked has a reject code indicating whether it is used in the solution or the reason for its rejection from the solution The reject value of 0 indicates the observation is being used in the position solution Values of 1 through 13 indicate the observation has been rejected for the reasons specified in GPSCard Solution Status on Page 52 In normal operation if the almanac indicates bad health in a satellite the receiver does not track it Also in normal operation if the almanac indicates good health and the ephemeris indicates bad health the receiver tracks the satellite but the receiver does not output the SAT log elevation and azi muth However on start up before the almanac is acquired
32. MAT User Manual Rev 2 17 Chapter 4 Device Menu 4 6 Exit To exit the MAT program select Device Exit from the main menu 18 Multipath Assessment Tool MAT User Manual Rev 2 Chapter 5 View Menu Once a device is open windows can be opened through the View menu or with the buttons on the toolbar Each View menu option is described here along with its window appearance and icon 5 1 Console H The Console window allows you to communicate directly with the WAAS type receiver through the serial connection port If MAT is in file playback mode you cannot issue commands to the device Although it is possible to issue commands and logs from the Console window it is not recommended See Logging Control on Page 21 for the recommended method of logging additional logs Warning Do not use the UNLOG command to stop logging any of the six logs used by MAT MPMB SATB DOPB POSB TM1B and ETSB If you do the multipath software may not work properly until the logs have been restored You may wish to issue logs that have no bearing on the multipath meter but are of interest to you With this screen you can send commands to the WAAS type receiver Refer to your receiver s operation manual for detailed information about WAAS type receiver commands and logging protocol See Logging Control on Page 21 for the recommended method of logging additional logs In the Console window following the SATA log satellite specifi
33. Multipath Assessment Tool MAT User Manual OM 20000054 Rev 2 Multipath Assessment Tool User Manual Publication Number OM 20000054 Revision Level 2 2001 07 31 Proprietary Notice Information in this document is subject to change without notice and does not represent a commitment on the part of NovAtel Inc The software described in this document is furnished under a license agreement or non disclosure agreement The software may be used or copied only in accordance with the terms of the agreement It is against the law to copy the software on any medium except as specif ically allowed in the license or non disclosure agreement No part of this manual may be reproduced or transmitted in any form or by any means electronic or mechanical including photocopying and recording for any purpose without the express written per mission of a duly authorized representative of NovAtel Inc The information contained within this manual is believed to be true and correct at the time of publica tion Multipath Assessment Tool Pinwheel Technology GPSCard and GPSAntenna are trademarks of NovAtel Inc NovAtel MEDLL MET and Narrow Correlator are registered trademarks of NovAtel Inc Microsoft MS MS DOS and Windows are registered trademarks of Microsoft Corporation IBM and PC are registered trademarks of International Business Machines Corporation 2001 NovAtel Inc All rights reserved Unpublished rights reserved
34. The Autocorrelation Function The ideal GPS receiver would have an infinitely wide receiver bandwidth BW which would allow the receiver to capture 100 of the GPS spread spectrum signal The normalized autocorrelation function for an infinitely wide BW is generally illustrated as shown in Figure 6 below Figure 5 Theoretical Normalized Auto correlation Function Auto correlation peak Pre correlation BW H assumed to be infinite Early slope 1 0 0 1 0 Code Correlation Offset in Chips The auto correlation peak is maintained by continually adjusting the locally generated code for maximum correlator output The unlimited BW provides a sharp correlation peak and steep early late slope that facilitates accurate error correction for the code lock loop also called Delay Lock Loop As the bandwidth is reduced the peak of the correlation function becomes more rounded In reality a GPS receiver would need an extremely wide band pass filter with a BW of at least ten times the C A code chipping rate to be capable of capturing gt 99 of the GPS spread spectrum signal For most GPS receivers this is generally not practical to achieve A 2 2 MEDLL NovAtel s MEDLL multipath reduction technology approaches the theoretical limits of multipath free GPS signal reception Multipath Estimating Delay Lock Loop MEDLL utilizes a combination of hardware and software techniques that are capable of reducing the combined effects of pseudorange
35. XE Select your WAAS type receiver and desired settings or your previously saved logging file by selecting Device Open Serial or Device Open File from the main menu 2 2 MAT Software Files The MAT program disk contains the following files that have been copied to the correct directories during the set up process These are shown below File Name File Type MAT EXE Program file MAT HLP Program help file README TXT Late breaking information about the program MAT LF License file KEYLIB32 DLL Program file MACHNML EXE Program file Multipath Assessment Tool MAT User Manual Rev 2 10 MAT Menus Overview Chapter 3 3 1 Menu Options The following table displays the menu options in the MAT program The following sections in this chapter describe the Window and Help menu options while the Device and View menu options are described in the chapters that follow Table 1 Menu Options Device View Window License Help Open Serial Console Tile Transfer License Contents Open File ASCII Messages Cascade Enable Retail Search for Help Active Config AR Status Close Close All Print Active Screen Print MAT Screen Print Preview MAT Screen Print Setup Logging Control Satellite Position Multipath Info Histogram D U Polar Plot Capture Control Statistics Arrange Icons 1 COM2 115200 2 MP july 6 gps 3 dervila_data gps 4 MP June 9 gps 5 COM1 115200 Exit
36. c data is entered in the command line The history of logs can be seen in the main area of the window Also shown are the menu items that appear when you right click anywhere in the window Multipath Assessment Tool MAT User Manual Rev 2 19 Chapter 5 View Menu 5 2 20 Console WAAS OF Xx log com alma onchanged log com cdsa onchanged log com clka onchanged log com posa ontime 1 log com dopa onchanged log com reca once log com sata onchanged G log com sata onchanged The Console window is where any error messages the WAAS type receiver sends will be displayed It is a good idea to monitor this window to be aware of any problems with the operation of the WAAS type receiver The console window is always open it cannot be closed Any ASCII logs that are requested from this window and directed to the appropriate COM port may be monitored in the ASCII Messages window The last 20 commands entered may be reviewed by using the up and down keys 4 in the far right scroll bar of the Console window Commande are listed from top to bottom in order of least to most recent The console window cannot be closed only minimized ASCII Messages Ea Ka The ASCII Messages window displays all of the ASCII records requested by you in the Console window and logged by the receiver The last 100 logs are held in a buffer which may be scrolled horizontally and vertically using the scrollbars atta
37. ched to the window or with the cursor keys The output of the window may be paused by pressing either the space bar or pause key All logs that arrive while the ASCII window is paused are not shown Displaying ASCII output resumes when you uncheck the Pause option after right clicking anywhere in the window Multipath Assessment Tool MAT User Manual Rev 2 View Menu Chapter 5 EJ ASCII Logs WAAS Paused of E 55L4 0 0 00 0 0 0 0 0000 0 0000 0 0000 99 0000 99 0000 99 0000 1 8 0 0 17 AGEA 41 247840 00 10 10600FF 21 24745990 970 0 116 130041096 779 0 006 3266 603 46 6 159 FRMA 41 247837 075 60050 4EB4 85 0D00000000000000000051 30 10NA 1 9557774066925048E 008 2 2351741790771479E 008 1 192092895507812E 007 1 192092 UTCA 1 2107193470001 22E 008 1 687538997430238E 01 4 405504 41 990 13 13 5 0D ALMA 1 5 10836E 003 405504 41 8 0003E 009 2 4650981E 000 1 7049612E 000 2 92585825E SALMA 2 2 01 716E 002 405504 41 8 18328 75700 BSE 001 2 1184638E 000 6 91 764901E 01 BSLA 0 0 00 0 0 0 0 0000 0 0000 0 0000 99 Print 99 0000 1 8 0 0 17 SALMA 3 1 29795E 003 405504 41 8 2061E Select all 74 001 1 10845654E 000 1 9047997E SALMA 4 5 19419E 003 405504 41 7 7409E 62E 000 5 4928347E 001 2 35384521E SALMA 5 2 01464E 003 405504 41 8 1718E ep 1 001 1 22195336E 001 2 28896936E 0 SALMA 6 6 79016E 003 405504 41 6 0918 1 Hear 36E 001 2 4068893E 000 3 0405904E 0 SALMA 1 10769E 002 405504 41 8 0918E Font 26E 001 2 091 4469E 00
38. d code 1 13 as shown on Page 53 11 Next PRN variable xx Checksum 1F variable CR LF Sentence terminator CR LF Example SATA 637 513902 00 0 7 18 168 92 5 52 9 582 0 6 308 12 55 48 0 737 0 15 110 36 5 87 16 010 0 11 49 63 40 29 0 391 0 2 250 05 58 89 12 153 0 16 258 55 8 19 20 237 0 19 118 10 49 46 14 803 0 1F CR LF Multipath Assessment Tool MAT User Manual Rev 2 67 Appendix B NovAtel Format Data Logs SATB Format Message ID 12 Message byte count 32 obs 32 Field Data Bytes Format Units ENS 1 Sync 3 char 0 header Checksum 1 char 3 Message ID 4 integer 4 Message byte count 4 integer bytes 8 2 Week number 4 integer weeks 12 3 Seconds of week 8 double seconds 16 4 Solution status 4 integer 24 5 Number of observations 4 integer 28 obs 6 PRN 4 integer 32 7 Azimuth 8 double degrees 36 8 Elevation 8 double degrees 44 9 Residual 8 double metres 52 10 Reject code 4 integer 60 11 Next PRN offset 32 obs x 32 where obs varies from 0 to obs 1 68 Multipath Assessment Tool MAT User Manual Rev 2 NovAtel Format Data Logs Appendix B BAG TMI1A B Time of 1PPS This log provides the time of the GPSCard IPPS in GPS week number and seconds into the week It also includes the receiver clock offset the standard deviation of the receiver clock offset and clock model status This log will output at a maximum rate of 1 Hz TM1A
39. d to record new information following the current information in the file or Abort to abandon this recording name and enter a new target file in the Enter Filename field The Logging Control window cannot be opened during file playback Multipath Assessment Tool MAT User Manual Rev 2 23 Chapter 5 View Menu 5 4 Satellite Position 24 The Satellite Position window graphically displays satellite geometry and the position of the sun The concentric circles are labelled 0 to 90 to represent elevations from the horizon to directly overhead respectively The azimuth direction to each satellite is mapped on a compass relative to true North When your cursor is over a satellite or the sun its azimuth and elevation are displayed on the MAT status bar Different DOP dilution of precision values of the geometry are displayed in each corner of the window DOP is defined as a numerical value expressing the confidence factor of the position solution based on current satellite geometry The lower the value is the greater the confidence in the solution DOP can be expressed in the following forms GDOP all parameters are uncertain latitude longitude height clock offset PDOP 3D parameters are uncertain latitude longitude height HDOP 2D parameters are uncertain latitude longitude TDOP clock offset is uncertain Position of Satellite and Sun ie EG The position of the sun is dependant on your time zone If
40. double 24 5 pdop 8 double 32 6 htdop 8 double 40 7 hdop 8 double 48 8 tdop 8 double 56 9 Number of satellites used 4 integer 64 10 Ist PRN 4 integer 68 11 Next satellite PRN Offset 68 sats x 4 where sats 0 to number of sats 1 46 Multipath Assessment Tool MAT User Manual Rev 2 NovAtel Format Data Logs Appendix B B 4 2 ETSA B Extended Channel Tracking Status These logs provide channel tracking status information for each of the GPSCard parallel channels This log is intended for status display only since some of the data elements are not synchronized together they are not to be used for measurement data Please use the RGEA B C SATA B and SVDA B logs to obtain synchronized data for post processing analysis If both the L1 and L2 signals are being tracked for a given PRN two entries with the same PRN will appear in the range logs As shown in Table 2 Channel Tracking Status word on Page 31 these entries can be differentiated by bit 19 which is set if there are multiple observables for a given PRN and bit 20 which denotes whether the observation is for L1 or L2 This is to aid in parsing the data ETSA Structure ETSA week seconds sol status obs prn ch tr status dopp C No residual locktime psr reject code prn ch tr status dopp GC No residual locktime psr reject code xx CR LF Field Field type Data Description Example 1 ETSA Log header ETSA 2 week GPS week number 85
41. esaaeseeeeeeseaeeseneeeee 52 5 Range Reject Codes A 53 6 MEDLE Status Bits etnia ia ee ak kru nika nova 57 7 Reference Ellipsoid Constants 0 ccccescceceeeeeeeeeeeeeeeeeesaeeeseaeeeseeeeseeeeeeaees 61 8 Transformation Parameters Local Geodetic to WGS84 0oooococccccccnoccnnccccccns 62 Multipath Assessment Tool MAT User Manual Rev 2 Figures 1 Real Time Data Collection cccccccscseceseeesseceesseseeeeseseaeeesescnaeeeeenseneeseeeeaas 8 2 GPS Signal Multipath Scenario 2 eee eee eee eee een nn 37 3 GPS Signal Multipath versus Increased Antenna Height 37 4 Example of C A Code Correlation 2 eeeeeeeeee eee eee n neen ete 38 5 Theoretical Normalized Auto correlation Function eee 39 6 Multipath Error Envelopes for Narrow Correlator vs MET vs MEDLL 40 Multipath Assessment Tool MAT User Manual Rev 2 Software License BY OPENING THE SEALED DISK PACKAGE ENVELOPE YOU ARE AGREEING TO BE BOUND BY THE TERMS OF THIS AGREEMENT IF YOU DO NOT AGREE TO THE TERMS OF THIS AGREEMENT PROMPTLY RETURN THE UNOPENED DISK PACKAGE AND THE ACCOMPANYING ITEMS TO NovAtel Inc 1 License NovAtel Inc NovAtel grants you a non exclusive license not a sale to use one copy of the enclosed NovAtel software on a single computer and only with the product whose model number and serial number appear on the envelope 2 Copyright NovAtel owns or has the right to sublicense all copyr
42. evation Plot dervila v Draw Right click anywhere in the plot s window to add or remove the azimuth or elevation grid lines to set the window default colours and change what appears in the plot The default view is the Show D U Average option Below is an example of the type of information that appears in the status bar when you position your mouse over any of the coloured bins in the plot Azimuth 126 4 Elevation 25 3 Number of Observations 100 Satellites Prn26 When the Show PsError Average option is selected the window displays the average of the pseudorange errors of PRNs in metres In both cases pseudorange error and D U ratio you can also select to view their minimums rather than their averages from the speed menu The minimum is an average of the least values and not an absolute minimum See Page 41 for an explanation of pseudorange error and D U ratio When the Change Plot Scale option is selected the following Range dialog appears so you can change the range values in the bins Changing polar plot scales for a particular view for example D U Min Multipath Assessment Tool MAT User Manual Rev 2 33 Chapter 5 View Menu 5 8 34 Average will store these scale settings on a per view basis You must then set your scale for each view in the polar plot Set D U Ranges AU ei a 4 DM P o y D D E 12 fis y gt z gt GA M SE ot ow rob no ol ol mf ol 4
43. he Statistics window to delete rows or add rows and specify the ranges A maximum of 9 rows can be present in the window The Samples column displays the number of samples used to calculate the mean and standard deviations This window is updated every second The Reset button restarts the statistics 5 9 Capture Control The capture control feature helps you to copy MAT screen images to a file Select View Capture Control from the main menu The Save Screen Captures To field is not editable directly you must browse for a file by pressing the ellipses button on the right To capture a screen only once click on the Capture Once button To capture a screen more than once decide the length of time between captures with the Save Screen Captures Every slider and press the Capture Ontime button This is useful for recording information over time especially if you cannot be there to watch the screen P lt The capture control will capture the active screen including any screen saver It is recommended you disable your screen saver program and turn off your monitor to capture the MAT images Multipath Assessment Tool MAT User Manual Rev 2 35 Chapter 5 View Menu Screen Capture CAWINNT Profiles dmadams Desktop scre ill ET E El Capture Onge _ Capture Ontime Gave s 49 screen bip Tf you select ONTIME the Capture Once button appears grey and clicking on the Stop Capture Button can stop the ontime trigger
44. i card system is used to sample the multipath signals as well as the direct path signals recognizing the difference between them then rejecting the multipath signals leaving only the desired direct path signal MEDLL is the most effective receiver technology available that reduces the combined effects of GPS L1 C A code and carrier phase multipath by as much as 90 Figure 2 GPS Signal Multipath Scenario Di III Lasnnnnnnnlannnnl Multipath Assessment Tool MAT User Manual Rev 2 37 Appendix A Radio Frequency RF And Multipath A 2 The Role of the GPS Receiver Correlator 38 Each GPS satellite transmits a unique pseudorandom noise PRN C A code coarse acquisition and P code precision As the P code is generally for military and special authorized use only this discussion is limited to C A code The C A code has a clocking rate chipping rate of approximately 1 023 MHz This chipping rate causes the GPS RF signal to have a main lobe 90 power spread spectrum of approximately 2 046 MHz As each satellite transmits on the same L1 carrier frequency they are differentiated only by their respective PRN codes To receive each GPS satellite PRN signal the earth station receivers have C A code generators that can match each of the satellite PRN codes As well the internal code generator must be clocked at a chipping rate that is as close as practical to that of the
45. ight trade secret patent and other proprietary rights in the software and the software is protected by national copyright laws international treaty provisions and all other applicable national laws You must treat the software like any other copyrighted material except that you may either a make one copy of the software solely for backup or archival purposes or b transfer the software to a single hard disk provided you keep the original solely for backup or archival purposes You may not copy the product manual or written materials accompanying the software 3 Restrictions You may not 1 copy other than as provided for in paragraph 2 distribute rent lease or sublicense all or any portion of the software 2 modify or prepare derivative works of the software 3 use the software in connection with computer based services business or publicly display visual output of the software 4 transmit the software over a network by telephone or electronically using any means or 5 reverse engineer decompile or disassemble the software You agree to keep confidential and use your best efforts to prevent and protect the contents of the software from unauthorized disclosure or use 4 Term and Termination This Agreement is effective until terminated You may terminate it at any time by destroying the software including all computer programs and documentation and erasing any copies residing on computer equipment If you do so you should inform N
46. ight click over the device icon in the MAT status bar and select Close from the list or select Device Close from the main menu and the active device is closed To close all open devices in MAT select Device Close All from the main menu 4 5 Print and Print Setup The contents of any MAT window may be printed A window must be selected with your cursor making it the active window before it can be printed To print an individual window select Print Active Window from the Device menu To print the whole MAT screen select Device Print MAT Screen from the main menu You can see how the MAT screen will appear before printing it by selecting Device Print Preview MAT Screen from the main menu Your print reguest will always go directly to the printer Plots are scaled to fill the entire available page area upon which they are to be printed Printing a graphic never spans multiple pages it is always performed in fit to page mode Keep in mind that the printed view may differ from the displayed view because the colours available on your printer may differ from those available on your computer monitor The Print Setup dialog allows you to alter your printer settings without actually printing anything This dialog is accessed by selecting Device Print Setup from the main menu When all your settings are correct click on the OK button in the Properties dialog and then on the OK button in the Print Setup dialog Multipath Assessment Tool
47. ion status 52 spectrum 38 39 speed 15 station receivers 38 statistics 34 status 16 17 device 14 MEDLL 54 serial port 16 sun 24 support 7 SV channel 28 system requirements 9 T TDOP 45 threshold 29 time conventions 43 conversion 72 of 1PPS 69 series plot 31 TM1A B 69 track 39 transformation 61 62 trigger option 22 54 trilateration 38 U undesired signal 39 UTC 30 43 69 V version 13 W warranty 6 wavelength 37 website 7 week 30 WGS84 58 61 62 65 76 Multipath Assessment Tool MAT User Manual Rev 2 NovAtel OM 20000054 Rev 2 2001 07 31
48. ist select your topmost PRN in the list with your mouse hold down the lt Shift gt key select your undermost PRN in the list and release the lt Shift gt key All the PRNs you have chosen will appear in your time series plot You can change the length of the x axis by inputting a value in the Enter Time Length of Plots in Seconds field The plots show parameters from the Multipath Info table against time The running average of the parameters are also shown on the plots except on Phase Azimuth and Elevation Below is an example of the D U Vs Time plot showing the speed menu that appears when you right click anywhere in the window SS SS S n Time Series Options Remove Prn Add Pin Remove Average Add Average MEMOVE ES Add All Averages na a 3 d NN QQ au gt SO a gt 0 508018 508068 Change PRN Scheme GPSS d ss Change Window Colours If there is more than one PRN in a plot each satellite representation will appear in a different colour The colour for an individual PRN between time series plots will stay the same They will not stay the same between different device configurations You can customize colour and line conventions for each PRN by selecting Change PRN Scheme from the speed menu The PRN Scheme Selector dialog will appear You can also customize the colour of the plot window foreground and background by selecting Change Window Colours from the menu The Colour Selector dialog will ap
49. istograms shown are Side You can also use the percentage option to show how many D U or pseudorange error observations from each satellite contribute to the bar height ih 5 6 Histogram 31 The PRN checkboxes along the right side of each histogram allow you to add and remove satellite PRNs from the histogram Multipath Assessment Tool MAT User Manual Rev 2 Chapter 5 View Menu IMHistograms of D U dB EGNOSMEDLLsmaller gps 32 m 2 j a W e F P m P F i WIN N N sch LD 0 A LN m OH eh e eee The default for the x axis is D U values You can change this to the pseudorange error in metres by right clicking with your mouse any where in the plot window and selecting Show Pseudorange Error from the speed menu Also on the speed menu is the Change Window Colours option See Pages 26 27 If there is more than one PRN in a plot each satellite representation will appear in a different colour The colour for an individual PRN between time series plots will stay the same They will not stay the same between different device configurations You can customize colour and line conventions for each PRN by selecting Change PRN Scheme from the speed menu The PRN Scheme Selector dialog will appear You can also customize the colour of the plot window foreground and background by selecting Change Window Colours from the menu The Colour Selector dialog will appear In both colour scheme dialogs right clicking
50. k anywhere on the Multipath Info window you can make a selection to bring up the Set Threshold dialog Specify a D U threshold and initialize a count of the number of threshold instances to allow et Threshold D U Threshold 2 of Threshold Hits fi Cancel Help If any satellite consecutively falls below the D U threshold more than the number of times specified in the of Threshold Hits field the row representing that satellite is coloured red If a satellite is unhealthy or no information is available for that satellite its row is coloured gray Over long time periods you can see which satellites are experiencing a level of multipath that is unacceptable to you by monitoring which are red Multipath Assessment Tool MAT User Manual Rev 2 29 Chapter 5 View Menu Select Reset DU Threshold Hits on the speed menu to reset the count of successive threshold instances Chane PRN Lock Dop Cc No az Jete Jo j 134 25 5 9 36 0 0 0 0 0 18 3 34 125 30 4603 5 4 6 4669 3 26 4190 2 0 0 1 23 3790 0 10 4655 5 9 3638 8 38 6 1894 7 50 8 2351 8 482 0 0 0 0 2959 9 45 1 3242 0 47 0 ee 31 1 27 6 0 0 26 9 29 4 Phase U UU 1 03 0 05 0 99 0 00 0 40 1 14 2 46 0 00 2 88 0 15 GPS Week 38 Seconds 508604 Z e DELAY e PHASE Delay between multipath and direct signal Time C A Chips see the x axi
51. l always be Byte Hex Decimal First AA 170 Second 44 68 Third 11 17 Multipath Assessment Tool MAT User Manual Rev 2 42 NovAtel Format Data Logs Appendix B 3 The Checksum is an XOR of all the bytes including the 12 header bytes with CRC 00 4 The Message ID identifies the type of log to follow 5 The Message byte count equals the total length of the data block including the header The following describes the format types used in the description of binary logs Size Size Description Type bytes bits char 1 8 The char type is used to store the integer value of a member of the representable character set That integer value is the ASCII code corresponding to the specified character int 4 32 The size of a signed or unsigned int item is the standard size of an integer on a particular machine On a 32 bit processor such as the NovAtel GPSCard the int type is 32 bits or 4 bytes The int types all represent signed values unless specified otherwise Signed integers are represented in two s complement form The most significant bit holds the sign 1 for negative 0 for positive and zero double 8 64 The double type contains 64 bits 1 for sign 11 for the exponent and 52 for the mantissa Its range is 1 7E308 with at least 15 digits of precision float 4 32 The float type contains 32 bits 1 for the sign 8 for the exponent and 23 for the mantissa Its range is 3 4E38 with at least 7 digits of
52. multipath errors by as much as 90 As well MEDLL does all this without the need to mount the antenna on a choke ring ground plane If you are using a GPS model 600 Pinwheel Technology antenna you will never need to mount it on a choke ring ground plane The MEDLL technology takes further advantage of NovAtel s parallel channel Narrow Correlator tracking technology as seen in Figure 6 on Page 40 It is unique in that it utilizes an array of narrowly spaced correlators distributed about the autocorrelation function whereby each satellite tracking channel is sampled by a dedicated correlator array Currently MEDLL is a 16 channel receiver This array distribution of correlator sampling allows the receiver to measure the shape of the received correlation function Using a maximum likelihood estimation technique MEDLL splits the received signals into their direct path and multipath components by determining the amplitude delay and Multipath Assessment Tool MAT User Manual Rev 2 39 Appendix A 40 Radio Frequency RF And Multipath phase angle of each of the composite signals Once the composite signal has been broken down into its components the signal with the least delay is determined to be the direct signal and all other signals with greater delay are considered to be the multipath components assuming the direct path signal is available and unobstructed MEDLL can effectively remove all multipath signals that have a propagati
53. ng is the predetermined hardware or software activity designed to establish or maintain two machines in synchronization Hardware handshaking uses voltage levels or pulses in wires to carry the handshaking signal Click in the Use Hardware Handshaking check box to turn hardware handshaking on Press the OK button to open the selected serial device on the specified COM port Once communications with the receiver have been successfully started the Console window will be automatically opened see Page 19 Multipath Assessment Tool MAT User Manual Rev 2 14 Device Menu Chapter 4 If MAT is opened using a serial port device it will automatically ask the receiver for the logs necessary to run all the MAT functions You can also request additional logs not needed by MAT by issuing a command to the receiver through the Logging Control window see Page 21 4 1 2 Open File When you select Device Open File from the menu the File Device Settings dialog appears File Device Settings EN Fil Browse IV Loop File Name IF Publications in progress Multipath S W dervila_data gp Playback spee fi 525 Logs Per Second is yl Cancel Help A file device reads logs from an existing file This is called file playback Use the Browse button in the File Device Settings dialog to select a playback file You can choose the play back speed from very slow slower than real time to very fast your processor ma
54. ns 2 No convergence 3 Singular AtPA Matrix 4 Covariance trace exceeds maximum trace gt 1000 m 5 Test distance exceeded maximum of 3 rej if distance gt 10 Km 6 Not yet converged from cold start Higher numbers are reserved for future use 52 Multipath Assessment Tool MAT User Manual Rev 2 NovAtel Format Data Logs Appendix B Table 5 Range Reject Codes 0 Observations are good 1 Bad satellite health is indicated by ephemeris data 2 Old ephemeris due to data not being updated during last 3 hours 3 Eccentric anomaly error during computation of the satellite s position 4 True anomaly error during computation of the satellite s position 5 Satellite coordinate error during computation of the satellite s position 6 Elevation error due to the satellite being below the cut off angle 7 Misclosure too large due to excessive gap between estimated and actual positions 8 No differential correction is available for this particular satellite 9 Ephemeris data for this satellite has not yet been received 10 Invalid IODE due to mismatch between differential stations 11 Locked out of the position solution by the user 12 Low Power satellite rejected due to low signal noise ratio 13 L2 measurements are not currently used in the filter 14 Reserved 15 16 17 GEO satellite not used in the position filter for RIMS C Multipath Assessment Tool MAT User Manual Rev 2 53 Ap
55. o the week The estimated standard deviations of the solution and current filter status are also included POSA Structure POSA week seconds lat lon hgt undulation datum ID lat std lon std het std sol status xx CR LF Field Field type Data Description Example 1 POSA Log header POSA 2 week GPS week number 637 3 seconds GPS seconds into the week 511251 00 4 lat Latitude of position in current datum in degrees 51 11161847 DD dddddddd A negative sign implies South latitude 5 lon Longitude of position in current datum in degrees 114 03922149 DDD dddddddd A negative sign implies West longitude 6 hgt Height of position in current datum in metres above 1072 436 mean sea level MSL H undulation Geoidal separation in metres where positive is above 16 198 spheroid and negative is below spheroid 8 datum ID Current datum ID see Table 7 Reference Ellipsoid 61 Constants on Page 61 and Table 8 Transformation Parameters Local Geodetic to WGS84 on Page 62 9 lat std Standard deviation of latitude solution element in 26 636 metres 10 lon std Standard deviation of longitude solution element in 6 758 metres 11 hgt std Standard deviation of height solution element in 78 459 metres 58 Multipath Assessment Tool MAT User Manual Rev 2 NovAtel Format Data Logs Appendix B 12 sol status Solution status as listed in Table 4 GPSCard Solution 0 Status
56. on Page 52 13 xx Checksum 12 14 CR LF Sentence terminator CR LF Example POSA 637 511251 00 51 11161847 114 03922149 1072 436 16 198 61 26 636 6 758 78 459 0 12 CR LF POSB Format Message ID 01 Message byte count 88 Field Data 1 Sync 3 char 0 header Checksum 1 char 3 Message ID 4 integer 4 Message byte count 4 integer bytes 8 2 Week number 4 integer weeks 12 3 Seconds of week 8 double seconds 16 4 Latitude 8 double degrees is 24 North is South 5 Longitude 8 double degrees is 32 East is West 6 Height 8 double metres with 40 respect to MSL H Undulation 8 double metres 48 8 Datum ID 4 integer 56 9 StdDev of latitude 8 double metres 60 10 StdDev of longitude 8 double metres 68 Multipath Assessment Tool MAT User Manual Rev 2 59 Appendix B NovAtel Format Data Logs 11 StdDev of height 8 double metres 76 12 Solution status 4 integer 84 60 Multipath Assessment Tool MAT User Manual Rev 2 NovAtel Format Data Logs Appendix B The following tables contain the internal ellipsoid parameters and transformation parameters used in the GPSCard The values contained in these tables were derived from the following DMA technical reports 1 TR 8350 2 2 TR 8350 2B Department of Defence World Geodetic System 1984 Its Definition and Relationships with Local Geodetic Systems Revised March
57. on a coloured square brings up a typical Windows colour selector dialog When you are finished your customisations press the OK button in any of these dialogs to save your changes for more information on this dialog The Freeze check box when selected stops the histogram from using any new data and therefore the histogram stays unchanged The freeze mode is useful to preserve the information currently in the histogram plot and still be able to fast forward and rewind the playback file to look at time series or other plots You can still change the type of histogram and remove PRNs in this mode When the Draw check box is selected it stops the histogram from changing however it is still accept ing new data The draw mode helps speed up the playback because your computer will not need to redraw the histogram every time new data is available The Reset button in the histogram window allows you to reset the histogram Multipath Assessment Tool MAT User Manual Rev 2 View Menu Chapter 5 5 7 D U Azimuth Elevation Polar Plot This polar plot represents different values for each satellite being tracked at that elevation and azimuth in the sky The boxes that are produced in the plot when the azimuth and elevation lines cross are referred to as bins in the manual Each bin represents 10 azimuth and 5 elevation The different colours in the plot indicate the different values z all PseudoRange Error Worst Case Azimuth El
58. on delay of greater than 0 1 chips relative to the direct path signal The remaining multipath effect on the C A code pseudorange measurements is now in the same order of magnitude as a P code GPS receiver Figure 6 Multipath Error Envelopes for Narrow Correlator vs MET vs MEDLL Tracking Error m e Multipath Signal Amplitude 0 5 Phase 0 180 deg 80 60 Standard Correlator 40 20 Delay C A Chips 40 Negative values indicate 180 degrees out of phase errors Multipath Assessment Tool MAT User Manual Rev 2 Radio Frequency RF And Multipath Appendix A A3 D U Ratio Given that MEDLL determines the amplitude of the direct signal and reflected signal you can create a ratio of the direct signal strength relative to the reflected signal strength This ratio is called D U and is correlated with pseudorange error due to multipath For information on monitoring the D U ratio see Multipath Info starting on Page 28 AA Pseudorange Error D U delay and phase can be used to generate a plot similar to Figure 6 on Page 40 The pseudorange error reported in MAT is an estimate of the pseudorange error for a receiver with NovAtel s Narrow Correlator tracking technology Pseudorange error is estimated from MEDLL parameters and not from a code minus carrier technique Multipath Assessment Tool MAT User Manual Rev 2 41 Appendix B NovAtel Format Data Logs WAAS type receivers are capable of generating man
59. osoft Mouse or compatible pointing device 1 4 What s New Here is a list of what is new in this manual since revision 1 e A new statistics window accessed by the G button see Section 5 8 Statistics on Page 34 e Details of the NovAtel logs used in the MAT software see Appendix B NovAtel Format Data Logs on Page 42 e The scope of the manual has changed from a WAAS receiver to any WAAS type receiver with MEDLL capability see back to Sections 1 1 and 1 2 of this chapter e For your convenience space saving and standardization this manual has been reformatted to anew 7 x 9 size Multipath Assessment Tool MAT User Manual Rev 2 9 Chapter 2 Installation The MAT software operates from your PC s hard drive You will need to install the software from the compact disk CD supplied by NovAtel 2 1 Quick Start 1 Start Microsoft Windows NT 2000 98 95 2 Execute the MAT auto install software by clicking on the Start button of your Windows screen and then select Run 3 In the Run dialog enter d setup exe where d is your CD drive SETUP EXE is the executable file from the CD Click on the OK button Alternatively click on the Browse button select setup exe from the files on your CD and click on the OK button The installation program will request that you confirm or re enter the name of the directory where MAT is to be loaded 4 Once MAT is installed start MAT by double clicking on its program icon MAT E
60. ovAtel in writing immediately This Agreement also will terminate if you do not comply with any of its terms or conditions Upon such termination you are obligated to destroy the software and erase all copies residing on computer equipment NovAtel reserves the right to terminate this Agreement for reason of misuse or abuse of this software 5 Warranty For 90 days from the date of shipment NovAtel warrants that the media for example diskette on which the software is contained will be free from defects in materials and workmanship This warranty does not cover damage caused by improper use or neglect NovAtel does not warrant the contents of the software or that it will be error free The software is furnished AS IS and without warranty as to the performance or results you may obtain by using the software The entire risk as to the results and performance of the software is assumed by you 6 For software UPDATES and UPGRADES and regular customer support contact the NovAtel GPS Hotline at 1 800 NOVATEL U S or Canada only or 403 295 4900 Fax 403 295 4901 e mail to support novatel ca website http www novatel ca or write to NovAtel Inc Customer Service Dept 1120 68 Avenue NE Calgary Alberta Canada T2E 885 7 Disclaimer of Warranty and Limitation of Liability a THE WARRANTIES IN THIS AGREEMENT REPLACE ALL OTHER WARRANTIES EXPRESS OR IMPLIED INCLUDING ANY WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
61. pear In both colour scheme dialogs right clicking on a coloured square brings up a typical Windows colour selector dialog When you are finished your customisations press the OK button in any of these dialogs to save your changes Choosing a line width greater than will make a dashed line appear solid Multipath Assessment Tool MAT User Manual Rev 2 View Menu Chapter 5 cam B T Mm WEE WI samu ree M l del ELLE Se ee eee a ea Dare ve SE IT gt Colas od Ecken 7 FAN Lino Width Lise Colnur Lise Eta s ite BEEBE EE ES any Ss M E Coker ci Fortypourd ie rel ge u pp SH Ma HI Ga The Reset Plot button in the plot window allows you to reset the plot You can change the length of the x axis and the amount of averaging by selecting Time Series Options from the speed menu The parameters are either plotted every time the device sends a value or averaged over a period of time user configurable in which case this average is displayed E meetme Window for multe Fila REN LD ist Rati Carrier Ni 50731 507344 507 BG 307394 207418 GPS Timeisecs Multipath Assessment Tool MAT User Manual Rev 2 27 Chapter 5 View Menu The averaging time in the Time Series Options dialog must be more than half the time length If it is not the following error message appears IN Invalid Input Retry If the plot does not include averaging only the Time Length op
62. pendix B NovAtel Format Data Logs B 4 3 MPMA B Multipath Meter Log This log is only available for MEDLL It outputs information that estimates the amount of multipath the antenna is experiencing and how well MEDLL has modelled the multipath signals It is recommended that this log be output only with the onnew trigger option There will be one log for every tracked satellite per epoch For example if eleven satellites are being tracked there will be eleven instances of this log every epoch MEDLL runs every second so one epoch is equivalent to one second MPMA MPMA week seconds prn chtrstat medllstat delay amplitude phase 1 in phase 12 in phase 1 quad phase 12 quad phase XX CR LF Field Field Type Data Description Example 1 MPMA Log header MPMA 2 Week Number GPS week number 0 3 Seconds of Week GPS seconds into the week 27 77 4 PRN Satellite identifier 29 5 Channel Tracking Status Channel tracking status bits see Page 51 6A84 6 MEDLL Status MEDLL status bits see Page 57 103 yi Delay Delay of multipath signal 1 08154941 8 Amplitude Amplitude of multipath signal 0 01731431 9 Phase Phase of multipath signal 0 00645047 10 1 in phase residual In phase residual value from correlator 1 0 00160142 Repeated for each correlator 22 12 in phase residual In phase residual value from correlator 12 0 00196318 23 1 Quadrature phase Quadrature phase residual value from
63. pes 40 messages 20 ETSA B 47 executable file 10 exit 14 18 F file 21 23 firmware 8 74 G GDOP 45 geodetic datum 61 geometry 24 gps time 43 H HDOP 45 header 30 Help 13 histogram 31 hold 22 HTDOP 45 in phase residual 54 installation 10 L license 6 11 12 link 17 list headers 30 logging control 22 locktime 28 logging control 21 logs 8 15 17 42 70 loop 15 16 matching 38 MEDLL 8 37 39 54 57 menu options 11 MPM log multipath meter 8 15 19 22 54 73 multipath information 26 28 29 37 39 54 N Narrow Correlator tracking technology 39 noise 38 North 24 NovAtel Inc 6 7 Multipath Assessment Tool MAT User Manual Rev 2 Index O open a device 14 P P code 38 40 PDOP 45 phase 30 38 40 54 Pinwheel Technology 37 39 playback 15 16 19 21 plot 15 17 26 31 polar 33 time 26 POSA B 58 prerequisites 9 print 17 PRN 24 28 38 contribution to the average 31 pseudorange error 31 33 41 Q quadrature phase residual 54 R radio frequency 37 range 37 measurements 38 reject codes 53 real time 8 reception 37 recording 21 22 reference ellipsoid constants 61 reflection 37 reject code 67 replay 15 reset 17 residuals 55 56 67 RF signal 38 S samples 35 SATA B 66 satellite position 24 saved file 14 screen capture 35 seconds 30 75 Index serial port 14 16 window arrangement 12 sigma 34 site selection 37 software 10 solut
64. s in file playback mode The name of the device configuration appears in the dialog header This window allows you to pause restart or choose a point in the file to begin the playback Use the slider or to be more precise fill in the Seconds seconds into the week and Week fields and click on the GO button You can turn on and off the loop feature by clicking on the Loop button looped arrow symbol You can also change the rate of playback in the Play Back Speed field using its slider The field box itself is for display purposes only and is not editable D lt When the GO button is pressed the software will attempt to start at the week and seconds specified in the Week and Seconds fields During this move no logs are read and your plot windows will not be updated Clicking on the More button shows you information about the type and status of logs that are being used in the playback There are three different types of log format Abbreviated ASCII ASCII and Binary The number of logs in the playback file or being received through a serial connection in each of these formats is shown A cyclic redundancy check CRC verifies ASCII and binary data The number of errors found by the CRC is shown The number of bytes that are not recognised as being any of the above formats is also shown You can use the Clear button at any time to restart producing these numbers from zero To show the status of a serial port when you are connected
65. s of the Multipath Error Envelopes Plot in Appendix A Page 40 The phase shift between the multipath and direct signal in the range 7 to 7 where T 3 1415927 radians The current GPS week represented by an integer 0 to 1023 and GPS seconds into the week from Sunday morning at 00 00 a m UTC are displayed in the status bar of the Multipath Information window The rows may be put in ascending or descending order for any column by clicking in the column header You may remove and add the headers that you see in the Multipath Information window at any time by right clicking anywhere on the Multipath Info window and choosing Select Headers from the speed menu 30 Multipath Assessment Tool MAT User Manual Rev 2 Chapter 5 View Menu E 3 x 2 o TE iag a ges L I m M1 x gt g 3 1 er MORK NNANNM L 0 E a PS Lp 3 a od E a a k lt m PRNs As One The Histogram window gives you a graphical representation of the D U and pseudorange error IMHistograms of D U dB EGNOSMEDLLsmaller gp s selecting Time Series Plots from the speed menu The Select Multiple Satellites dialog appears See its description in the Plots section starting on Page 25 distribution For an explanation on D U and pseudorange error please see Page 41 There are three Right clicking anywhere in the window will allow you to open a time series plot of your choice by types of histograms available The h
66. tion is shown Time Length Cancel Help 100 5 5 Multipath Info The data in the Multipath Info window is arranged in tabular format with each row representing a different satellite The window is updated with new data every time it gets a complete set of data for all the satellites being tracked The Multipath Info table displays a set of parameters related to multipath 28 e Chan e PRN e Lock e Dop C No e AZ SV receiver channel number The Pseudorandom Noise Number that is unique for each satellite Locktime number of seconds of continuous tracking Doppler frequency Carrier to Noise density ratio 0 to 99 dB Hz 0 when not tracking Azimuth The horizontal direction of a celestial point from a terrestrial point expressed as the angular distance from 000 reference clockwise through 360 The reference point is generally True North Multipath Assessment Tool MAT User Manual Rev 2 View Menu e ELE e D U Set DU Threshold Reset DU Threshold Hits Select Headers Time Series Plots Chapter 5 Elevation The angle from the horizon to the observed position of a satellite Desired Undesired MEDLL splits the received signals into their direct path desired and multipath undesired components Generally the higher the D U ratio is the more accurate the pseudorange will be D U is the relative power of the desired signal compared to the undesired signal If you right clic
67. to a WAAS type receiver select Device Status from the main menu or right click over the device icon in the far right of the status bar and select Status from the list The following dialog appears with the name of the device configuration in Multipath Assessment Tool MAT User Manual Rev 2 Device Menu Chapter 4 the dialog header Abbreviated fi 5 fo Ascii Binary 55288 FE CRC Errors fo BaudFiate 115200 7 More Unknown bytes 3 Clear This status dialog shows the status of the connection to the receiver and the current baud rate bps The lights turn green when the PC is transmitting or receiving data respectively The Comm Error light glows red when there is an error in the communication link between the PC and MEDLL receiver Clicking on the More button shows you information about the type and status of logs that are being logged There are three different types of log formats Abbreviated ASCII ASCII and Binary The number of logs being received through the serial connection in each of these formats is shown A cyclic redundancy check CRC verifies ASCII and binary data The number of errors found by the CRC is shown The number of bytes that are not recognised as being any of the above formats is also shown You can use the Clear button at any time to reset these numbers to zero 4 4 Close and Close All Currently open devices can be seen in the far right side of the MAT status bar To close a current device r
68. udo Random Noise number RAM Random Access Memory RF Radio Frequency TDOP Time Dilution Of Precision UTC Coordinated Universal Time UHF Ultra High Frequency VDOP Vertical Dilution of Precision WAAS Wide Area Augmentation System Multipath Assessment Tool MAT User Manual Rev 2 73 Numerics Ipps 69 A accuracy 38 39 acronyms 73 amplitude 39 54 56 antenna 37 39 58 ascii 16 17 54 format 42 messages 20 autocorrelation 39 automatic logs 15 averaging time 27 28 azimuth 24 28 35 66 bandwidth 39 baud rate 17 73 binary 16 17 42 56 71 bps 17 C C A code 37 40 C NO 28 capture control 35 carrier phase 37 CD 10 channel 28 37 38 tracking status 51 54 checksum 42 43 chipping rate 38 39 choke ring 39 clock 45 69 clocking rate 38 close device 17 code generator 38 colour of rows 29 communication link 17 configuration 14 16 Multipath Assessment Tool MAT User Manual Rev 2 console window 19 continuous tracking 28 conversions 71 coordinated universal time UTC 30 correlator 8 37 39 54 customer service 7 cyclic redundancy check CRC 16 D D U ratio 26 29 34 56 datum 62 65 delay 30 39 54 lock loop 39 desired signal 37 39 device 14 16 19 active 14 close 17 icon 14 17 open 14 serial port 15 settings 15 status 14 dilution of precision DOP 24 DOPA B 44 Doppler frequency 28 E elevation 24 29 35 67 ellipsoid 61 65 e mail 7 error 16 17 envelo
69. y NovAtel format output logs in either ASCII or binary format The following log descriptions are listed in alphabetical order Each log first lists the ASCII format then the binary format description B 1 ASCII Log Structure Log types ending with the letter A are output in ASCII format e g POSA The structures of all ASCII logs follow the general conventions as noted here 1 The lead code identifier for each record is 2 Each log is of variable length depending on amount of data and formats 3 All data fields are delimited by a comma with the exception of the last data field which is followed by a to indicate end of message data 4 Each log ends with a hexadecimal number preceded by an asterisk and followed by a line termination using the carriage return and line feed characters e g xx CR LF This 8 bit value is an exclusive OR XOR of all bytes in the log excluding the identifier and the asterisk preceding the two checksum digits Structure XXXX data field data field data field xx CR LF B 2 Binary Log Structure Log types ending with the letter B are output in binary format e g POSB The structures of the binary logs follow the general conventions as noted here 1 Basic format of Sync 3 bytes Checksum 1 byte Message ID 4 bytes unsigned integer Message byte count 4 bytes unsigned integer Data x bytes 2 The Sync bytes wil
70. y be going at maximum speed with the Playback Speed scale bar The Logs Per Second field is for displaying the chosen speed and is not editable The most important factors affecting this rate are the performance of your PC s hardware and the number of plot windows that are open see Plots on Page 25 For example a Pentium 133 MHz computer s fastest rate of file playback with several Time Series windows open is approximately real time However a Pentium II 400 MHz computer s rate of playback with several Time Series windows open is about 10 times faster than real time Click in the Loop checkbox if you want MAT to continue to replay your file from the beginning when it comes to the end of the file MAT uses 6 binary logs in its playback mode MPMB SATB DOPB POSB TM1B and ETSB If you use the Logging Control window these logs will be saved automatically For a description of these logs please see Appendix B starting on Page 42 4 2 Active Config To view a currently active configuration select Device Active Configuration and click on the device to be viewed or right click over its icon in the bottom right of the MAT window and choose Select from the options Multipath Assessment Tool MAT User Manual Rev 2 15 Chapter 4 Device Menu 4 3 Status 16 Select Device Status from the main menu or right click over the device icon in the far right of the status bar and select Status for the Status window to appear when MAT i
71. your inquiry attach additional sheets if needed You may photocopy and fax this page call or mail the above information to the address listed below Contact your local NovAtel dealer first for more information To locate a dealer in your area or if the problem is not resolved contact NovAtel Inc directly using one of the following methods Call the NovAtel GPS Hotline at 1 800 NOVATEL North America or 403 295 4900 international Fax 403 295 4901 E mail support novatel ca Website http www novatel ca Write NovAtel Inc Customer Service Dept 1120 68 Avenue NE Calgary Alberta Canada T2E 8S5 Multipath Assessment Tool MAT User Manual Rev 2 7 Chapter 1 Introduction 1 1 Congratulations Congratulations on purchasing your Multipath Assessment Tool referred to as MAT in this manual MAT is a Windows based program that is designed to display multipath parameters along with signal and satellite information in order to monitor undesirable multipath effects The software works with real time data from the serial port of a WAAS type receiver with Multipath Meter firmware within it or with data previously saved to a file MAT uses a multipath meter feature from within the Multipath Estimating Delay Lock Loop MEDLL portion of a WAAS type or Portable MEDLL receiver MEDLL utilizes innovative correlator delay lock loop techniques The correlator is the heart of the GPS receiver C A code tracking loop MEDLL

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