Welcome to the California Spatial Reference Center

The California Spatial Reference Center (CSRC) is responsible for “Establishing and maintaining an accurate state-of-the-art network of GPS control stations for a reliable spatial reference system in California.” The CSRC was established in 1997 as a partnership with surveyors, engineers, GIS professionals, the National Geodetic Survey (NGS), the California Department of Transportation (Caltrans), and the geodetic and geophysical communities.

The CSRC also maintains the California Real Time Network (CRTN), established in 2003 to (1) provide base station support for precise positioning (e.g., RTK surveys) and spatial referencing, (2) support research into earthquake early warning and response systems. CRTN rebroadcasts real-time data streams from multiple servers to registered users.

The CSRC is operated by the Scripps Orbit and Permanent Array Center (SOPAC) located at the Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics (IGPP) at Scripps Institution of Oceanography.

CSRC Community Notices

  • October 17, 2019: Recognition of Chris Walls, UNAVCO/NOTA  Southwest Project Manager  at CSRC Coordinating Council Fall Meeting in Sacramento. An excerpt:  "Without the contributions and partnership of UNAVCO, realized through the tireless efforts of Mr. Walls and the UNAVCO staff, the California Geospatial Community would not have access to the robust geodetic infrastructure that exists today in the form of the CSRN and CRTN. On behalf of that community, and the CSRC, we extend a heartfelt thank you to Chris, UNAVCO and the National Science Foundation."
  • June 26, 2019: Scott P. Martin, CSRC Executive Committee member and California Geodetic Coordinator for the National Geodetic Survey, was recognized as an "NGS Partner" with an accompanying NOAA commemorative disk "in recognition of his significant and much-appreciated contributions to the geospatial community."
  • December 14, 2017: California’s GIS Council endorses the recommendations of the report “Maintaining California’s Geodetic Control System Strategic Assessment” prepared by the Geodetic Control Working Group.
    • February 26, 2018: Endorsed by League of California Surveying Organizations (LCSO)
    • March 28, 2018: Endorsed by County Engineers Association of California (CEAC)
    • April 9, 2018: Endorsed by American Council of Engineering Companies California (ACEC)
    • April 27, 2018: Endorsed by California’s Land Surveyor’s Association (CLSA)
    • April 30, 2018: Endorsed by Urban and Regional Information Systems Association (URISA)
    • May 5, 2018: Endorsed by Esri
  • CRTN transitioned to CSRS Epoch 2017.50 (NAD83) on March 1, 2018.
  • The CRTN Southern California server has a new IP (updated February 6, 2018):
  • The CRTN Northern California server has a new IP (updated August 5, 2017):
  • CRTN Registration: Allow 7-10 days for an account
  • Give a Gift to CRTN

Upcoming CSRC Events

June 17, 2021: CSRC Coordinating Council Spring Meeting (virtual)


June 16: The CSRC 2017.50 map is now accessible via QR code. Use the QR code below. (If needed, instructions are available here.)

May 6, 2021: Datum Epochs, And How to Understand Them is now available online.

January 15, 2020: The CSRC Policies (pdf) and Bylaws (pdf) are now available online.

December 29, 2019: Overview of geodetic datums: Epoch Date vs Kinematic

August 30, 2019: Update on Ridgecrest July 4 and 6, 2019 earthquakes. Details. Download coseismic offsets (corrected 11/4/2019).  Download Epoch 2019.55 coordinates for affected stations.

In February 2018, the CSRC published a new geodetic datum for California called “CSRS Epoch 2017.50 (NAD83)” under a Caltrans contract to SIO/SOPAC. The new epoch-date coordinates have been embedded in the RTCM 3.0 data streams since March 1, 2018.