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 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
CRTN Community Notice
• CRTN has completed the transition to CSRS Epoch 2017.50 (NAD83), effective March 1, 2018
• The CRTN Southern California server has a new IP (updated February 6, 2018): 22.214.171.124
• The CRTN northern California server has a new IP (updated August 5, 2017): 126.96.36.199
In February 2018, the CSRC published a new geodetic datum for California called “CSRS Epoch 2017.50
under a Caltrans contract to SIO/SOPAC.
CRTN is now transmitting CSRS Epoch 2017.50 (NAD83) coordinates, effective March 1, 2018