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 GISA base station meets National Geodetic Survey (NGS) CORS guidelines and is incorporated into the NGS national CORS network.

    GISA continuously collects multi-constellation GPS/GNSS signals (GPS, GLONASS, Galileo and BeiDou) and stores them in data files on a secure Esri server accessible to the public via the Esri website GNSS Site. This website provides access to logged GPS/GNSS data in proprietary Trimble T02 and Receiver Independent Exchange (Rinex) formats. Prior to 03-March-2021 GISA logged data were stored in T02 and Rinex version 2.11 format and beginning 04-March-2021 GISA logged data are stored in T02 and Rinex version 3.04 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.

  2. Data

    3. Logged data in Trimble T02 and Rinex versions 2.11 or 3.04 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


and 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)

Uncompressed daily (24-hour) data are logged immediately after midnight of GPS (UTC) time and stored under the same two
directories as the hourly data files with naming convention (for the Rinex, Version 3.04 files refer to the Rinex long
filename naming convention here:

	/native/yyyy/ddd/ssss/ssssdddad.to2
	/rinex/yyyy/ddd/ssss/GISA00USA_R_YYYYDDDHHMM_PPP_RRR_TT.rnx

where

	GISA00USA = site, station and country code
	R = data source (Rinex)`
	YYYY = four digit GPS year
	DDD = the GPS day of year
	HH = hour
	MM = minute
	PPP = nominal file period (i.e. 01H = 1 Hour, 01D = 1 Day, etc.)
	RRR = data rate (i.e. 15S = 15 Seconds, etc.)
	TT = file type (i.e. MO = Mixed RINEX GNSS observation file, MN = Mixed RINEX GNSS navigation file, etc.)

For example:

	GISA00USA_R_20210630000_01D_15S_MO.rnx

	is a mixed observation (_MO) Rinex (.rnx) file containing 1 day (24-hours) of data (_01D) at 15-second data rate (_15S)
	collected on day 063 (04-March-2021) in year 2021 (_20210630000) collected at station GISA in the USA (GISA000USA); and

	GISA00USA_R_20210631100_01H_30S_MN.rnx

	is a mixed navigation (_MN) Rinex (.rnx) file containing 1 hour of data (_01H) at 30-second data rate (_30S) collected
	on day 063 (04-March-2021) hour 11:00 in year 2021 (_20210631100)collected at station GISA in the USA (GISA000USA).
  3. Data Download and Retention

    4. 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.

  4. Site Name Change

    5. On GPS Day 314 of year 2011 (15-November-2011), the site name was changed from gis1 to gisa. Prior to GPS Day 314 (15-November-2011) all files will reflect site name gis1; after GPS Day 314 (15-November-2011) all files will reflect site name gisa. On GPS Day 314 ((15-November-2011) files exist for both site names gis1 and gisa.

  5. Real-Time Data

    6. GISA continuously tracks GPS/GNSS signals and makes them publically available over the internet in real-time in RTCM version 2.3, RTCM version 3.X and RTCM version 3.2 MSM5 streams. These streams supply DGPS, RTK and multi-constellation MSM5 correction data respectively 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, "gisar30" for RTCM version 3.X or "gisaMSM5" for RTCM MSM5 data streams; no authentication is required.

  6. Antenna Site Logs

    7. Gisa Site Log

  7. GPS Data

    8. GNSS Data in raw Trimble t02, Rinex 2.11 and Rinex 3.04 format

  8. Point of Contact

    9. 		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 or Esri IT Team