Stanford GPS/GNSS Matlab Platform Overview

Stanford GPS/GNSS Matlab Platform (SGMP) is an integrated research platform developed at Stanford University for GPS research activities. The platform provides tools for utilizing GPS/GNSS measurements in various formats, converting positioning databases, simulation capabilities, and user interfaces for easy control and data conversion. By leveraging the power of Matlab, researchers can seamlessly conduct GPS experiments and work with different data formats efficiently.

• GPS research
• Matlab platform
• Stanford University
• Positioning databases
• GNSS measurements

lung_ara Follow

Uploaded on Oct 04, 2024 | 0 Views

Download Presentation

Please find below an Image/Link to download the presentation.

The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author. Download presentation by click this link. If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.

Presentation Transcript

1. Stanford GPS/GNSS Matlab Platform Integrated Research Platform with Unbounded Positioning Database February 2009 Juyong Do Stanford University

2. Stanford GPS/GNSS Matlab Platform Stanford GPS Matlab Platform (SGMP) is a platform that enables you to use GPS/GNSS measurements in various formats for your GPS research activity. Measurement Interface GPS Simulator GPS/GNSS Measurement User Interface 2 Stanford University - GPS Laboratory

3. Key Aspects of SGMP Everything Matlab Matlab has been most popular for GPS/GNSS research. So let s move everything to the world of Matlab for seamless and uninterrupted research. Access to Unbounded Database Convert positioning database in various formats (NSTB, NMEA, RINEX ) to a single format in Matlab. Integrated Platform SGMP is a platform intended for GPS simulation as well as measurement interface. Any simulation based on SGMP format can operate under SGMP platform. 3 Stanford University - GPS Laboratory

4. Components in SGMP Measurement Interface GPS Simulator GPS/GNSS Measurement User Interface Measurement Interface Convert various formats to SGMP format. GPS Simulator Position estimation, RAIM research User Interface Provides user control. 4 Stanford University - GPS Laboratory

5. Measurement Interface An interface to various formats of GPS intermediate measurements (psuedorange). All supported formats of measurements are converted to a Matlab format. NSTB Database Measurement Interface SGMP Database RINEX Database NMEA Database Extension to other sensors (TV, WiFi, INS )? 5 Stanford University - GPS Laboratory

6. Input Formats: NSTB, National Satellite Test Bed (NSTB) A data format for Test Bed Reference Station (TRS) and WAAS Reference Stations (WRS) data. The recorded data includes GPS measurements; ephemeris and almanac data; GEO measurement and WAAS broadcast data; as provided by the GPS receivers at the Reference sites. Receiver Independent Exchange Format (RINEX) A data interchange format for raw satellite navigation system data. This allows the user to post-process the received data (usually with other data unknown to the original receiver, such as better models of the atmospheric conditions at time of measurement) to produce a more accurate solution. National Marine Electronics Association (NMEA) NMEA 0183 (or NMEA for short) is a combined electrical and data specification for communication between marine electronic devices such as echo sounder, sonars, anemometer (wind speed and direction), gyrocompass, autopilot, GPS receivers and many other types of instruments. It has been defined by, and is controlled by, the U.S.-based National Marine Electronics Association. 6 Stanford University - GPS Laboratory

7. NSTB Stations 7 Stanford University - GPS Laboratory

8. Output Format: SGMP info Structured data tree rx contains information and measurements by a receiver during a specific time frame. rx.info, rx.meas, and rx.aiding. meas tx rx eph aiding waas almanac iono utc tms Field Description tus info receiver and data file information sqm meas measurements by receiver aiding aiding information from external sources sqminfo waasstatus 8 Stanford University - GPS Laboratory

9. rx.info rx.infocontains receiver specific static information such as receiver type and the start and end time of overall data file. Field Description id User defined receiver identification number sitename receiver site name type receiver type initpos initial position of receiver in XYZ (meter) and equivalent to true position for stationary receiver gpswk reference time in gps week number starttow start time of reception in time of week (second) endtow end time of reception in time of week (second) 9 Stanford University - GPS Laboratory

10. rx.meas.tx rx.meas.txcontains transmitter specific measurements for given reference measurement time. Field Description prn transmitter identification number. prn for GPS satellites numch number of channels for this transmitter pr pseudo-range (meter) cr carrier-range (meter) dp Doppler (meter/second) snr signal-to-noise ratio (dBHz) slip cyclic slip counter (0-7) 10 Stanford University - GPS Laboratory

11. rx.aiding rx.aidingcontains aiding information provided by external sources such as GPS satellites and WAAS satellites. Includes eph, waas, almanac, iono, utc, tms, tus, sqm, sqminfo,and waasstatus. Field Description eph ephemeris and clock parameters from GPS navigation message waas WAAS broadcast message almanac almanac message iono ionosphere (Klobuchar) message utc UTC message tms TMS to TUS message tus TUS to TMS message sqm SQM message sqminfo SQM information message waasstatus WAAS subsystem status message 11 Stanford University - GPS Laboratory

12. GPS Simulator Now We re Ready to Rock! GPS Simulator is a block allocated for signal processing functionalities based on data from Measurement Interface. A sample program is provided which can be modified according to user s needs. GPS Simulator PosFix Engine SGMP Database Multipath Simulation RAIM Evaluation 12 Stanford University - GPS Laboratory

13. Example: Position Fixes Position Estimation "Acv EPak 1330 1514 00 0.mat" at (41.0, -124.1, 56.2m) "Acv EPak 1330 1514 00 0.mat" at (41.0, -124.1, 56.2m) 15 2 East (m) 100.0% success with 1.0m (2drms) 0 10 -2 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 5 North (m) 5 0 North (m) -5 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 10 Up (m) 0 -5 -10 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 2 -10 Clock (us) 1 -15 0 -15 -10 -5 0 5 10 15 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 East (m) Time (hour) 13 Stanford University - GPS Laboratory

14. Example: Position Fixes (contd) "Acv EPak 1330 1514 00 0.mat" at (41.0, -124.1, 58.7m) 30 ( , ) = -0.0 0.5 "Acv EPak 1330 1514 00 0.mat" at (41.0, -124.1, 56.2m) 20 East 10 6 0 -1.5 -1 -0.5 0 0.5 1 1.5 4 20 2 ( , ) = 0.0 0.6 Up (m) North 0 10 -2 0 -4 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 -6 30 4 ( , ) = -0.0 1.5 2 2 20 1 0 Up 0 10 -2 -1 -4 -2 North (m) East (m) 0 -5 -4 -3 -2 -1 Position error (m) 0 1 2 3 4 5 14 Stanford University - GPS Laboratory

15. How it works: Setting Up Go to waas.stanford.edu Download and unzip SGMP.zip You ll see following directories created under /SGMPrelease: /SGMPrelease/document /SGMPrelease/measurement interface /SGMPrelease/simulator /SGMPrelease/user interface 15 Stanford University - GPS Laboratory

16. How it works: Parsing Getting NSTB Data Go to http://www.nstb.tc.faa.gov/DisplayNSTBDataDownload.htm Download and unzip NSTB files Move the unzipped NSTB files to /SGMPrelease/measurement interface/data/nstb Parsing To parse all NSTB files, use /SGMPrelease/measurement interface/batchparseNSTB.m To parse a NSTB file, use /SGMPrelease/measurement interface/parseNSTB(filename, starthour, endhour, crccheck) ex) rx = parseNSTB( 'Acv_EPak_1330_1514_00', 1, 5, 0); %parse NSTB file from 1 hour to 5 hour without CRC checking 16 Stanford University - GPS Laboratory

17. How it works: Positioning Positioning After parsing NSTB files to SGMP files (located under /SGMPrelease/measurement interface/data/parsed), we are ready to rock! Start Matlab and go to /SGMPrelease/simulator/ Execute batchPosfixSGMP.m Alternatively, use posfixNSTB(filename) Results Go to /SGMPrelease/simulator/result/posfix/ Check out *.mat, *.fig, or *.eps files for results 17 Stanford University - GPS Laboratory

18. Summary SGMP (Stanfor GPS/GNSS Matlab Platform) is a Matlab based platform providing access to multi- format positioning database. SGMP enables you to tap into existing and ever- growing database regardless of formats. Standardized format (SGMP) opens door to research collaboration and connection b.t. generations of students. 18 Stanford University - GPS Laboratory

19. Whats next Measurement Interface Support for NMEA, RINEX, Extension to other sensors such as TV, WiFi, GPS simulator Add more blocks (RAIM simulation, differential positioning, ) For example, NSTB provides dual frequency code and carrier measurements. Lots of possibilities. User Interface Implement a Per -friendly GUI? 19 Stanford University - GPS Laboratory

20. Reference 1. NstbDataFormat1103.doc Description of NSTB format 2. www.nstb.tc.faa.gov/DisplayNSTBDataDownloa d.htm NSTB data files are provided. 3. www.mathworks.com/access/helpdesk/h elp/techdoc/ref/struct.html Matlab structure type is described. 1. SGMP.zip 20 Stanford University - GPS Laboratory

21. Thanks! Thanks to Euiho and Grace for their earlier works for NSTB data. Thanks to Todd, Juan and Per for their inputs to SGMP. Thank you, everyone! 21 Stanford University - GPS Laboratory