ESRI GPS/GNSS Base Station Data Access

  1. Background

  2. Esri has installed a permanent building mounted GPS/GNSS base station in Redlands, California named "gisa". GISA operates a Trimble NetR9, dual-frequency GPS/GNSS receiver with Zephyr Geodetic Model 2 antenna. The base station meets National Geodetic Survey CORS guidelines and is in the process of being incorporated into the national CORS network.

    GISA continuously collects GPS/GNSS signals and stores them in data files on a secure Esri server accessible to the public via the Esri website http://gnss.esri.com (GNSS Site). This website provides access to logged GPS/GNSS data in proprietary Trimble T02 and Receiver Independent Exchange (Rinex) version 2.11 format. Surveyors, GIS users, engineers, scientists, and the public at large that collect GNSS data can combine their data with GISA base station data to improve the precision of their positions.

  3. Data

  4. Logged data in Trimble T02 and Rinex version 2.11 format are freely available at GNSS Site. Uncompressed hourly data are logged immediately after each hour of GPS (UTC) time and stored under two directories on GNSS Site for each GPS day: /native and /rinex. The directory structure is as follows:
    	/native/yyyy/ddd/ssss/ssssdddh.to2
    	/rinex/yyyy/ddd/ssss/ssssdddh.yy[t]
    
    where 
    
    ssss = the four-character site ID
     ddd = the GPS day of year
    yyyy = four digit GPS year
       h = a letter that corresponds to an hour-long GPS time block according to:
    00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23
     a  b  c  d  e  f  g  h  i  j  k  l  m  n  o  p  q  r  s  t  u  v  w  x
    
    
    For the Rinex, Version 2.11 files:
    
    yy = the last two digits of four digit GPS year (e.g. 2011 is 11)
     t = the file type as:
         o - observation
         n - navigation (GPS)
         g - navigation (Glonass)
    						
  5. Data Download and Retention

  6. To download data, go to GNSS Site, navigate to the desired directory, right click on the desired file and save to the desired location on your local machine. Files must be downloaded one by one; simultaneous multiple file download is not available at this website.

    Logged data files will remain on GNSS Site for one year after its GPS Day of posting. After this, both the native and Rinex data will be archived and removed from GNSS Site. To obtain data from the archive contact the ESRI GNSS Team.

  7. Site Name Change

  8. On GPS Day 314 of year 2011, the site name was changed from gis1 to gisa. Prior to GPS Day 314 all files will reflect site name gis1; after GPS Day 314 all files will reflect site name gisa. On GPS Day 314 files exist for both site names gis1 and gisa.

  9. Real-Time Data

  10. GISA continuously tracks GPS/GNSS signals and makes them publically available over the internet in real-time in RTCM version 2.3 and RTCM version 3.0 formats. These streams supply DGPS and RTK correction data in real-time and are available for public use. To access gisa real-time data streams via Networked Transport of RTCM via Internet Protocol (NTRIP) use gisa real-time data, and select mountpoint "gisar23" for RTCM version 2.3 or "gisar30" for RTCM version 3.0 data streams; no authentication is required.

  11. Antenna Site Logs

  12. gisa

  13. GPS Data

  14. GPS Data in raw and Rinex 2.11 format

  15. Point of Contact

  16.      Agency                   : Environmental Systems Research Institute
         Preferred Abbreviation   : Esri
         Mailing Address          : 380 New York Street
                                  : Redlands CA 92373
         Primary Contact
           Contact Name           : 
           E-mail                 : ESRI GNSS Team