CRTN Data Policy

  • CRTN offers one free RTCM data stream per organization for single-base positioning with respect to the California Spatial Reference System (CSRS). Users must register with the CSRC to obtain access; to register, click here. Multiple data streams are available to Contributing and Consortium members. For more information, please click here and contact Maria Turingan (
  • CRTN is divided into 4 subnetworks according to California Coordinate System (CCS83) zones, accessed through two IPs and 4 ports (2 ports per IP):

    Southern California, Zone 6:

    Southern California, Zone 5:

    Northern California, Zones 3-4:

    Northern California, Zones 1-2:

  • CRTN Station List: for the breakdown of stations and relevant information, please click here to download the current Excel file.

Additional Updates

  • Contributing Members donate $1,000 annually, which provides access to a second NTRIP account for real-time access to RTCM 3.0 data (all users have free access to a single account). Additional access increases by $1,000 per account. Please note that contributing members do not participate in oversight/management of the network. All donations are used towards operating and maintaining CRTN and our data services. If you or your organization would like to donate, please go click here.
  • CRTN Consortium Members contribute $15,000 annually, which provides access to any 20 real-time CGPS sites 24/7. This membership has voting privileges on the CRTN Consortium, which oversees the development and management of the network.
  • Statewide CRTN Consortium Members contribute $150,000 annually, which provides access to all real- time CGPS sites 24/7. This membership has 3 voting privileges on the CRTN Consortium, which oversees the development and management of the network.

Participating Organizations: American Congress on Surveying and Mapping (ACSM) • American Council of Engineering Companies (ACEC) California • American Society of Photogrammetry and Remote Sensing (ASPRS) • BAsin and Range GEodetic Network (BARGEN) • Bay Area Regional Deformation (BARD) • Bureau of Land Management (BLM) • California Coastal Commission (CCC) • California Department of Water Resources (DWR) • California Land Surveyors Association (CLSA) • California State University Fresno • CalTrans • Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE) • City of Los Angeles, Department of Public Works • City of Vacaville • County Engineers Association • East Bay Municipal Utility District (EBMUD) • ESRI • Geographical Information Systems Consultants • League of California Surveying Associations • Metropolitan Water District of Southern California (MWD) • National Oceanic and Atmospheric Administration (NOAA) • NOAA’s National Ocean Service (NOS) National Geodetic Survey (NGS) • Office of Management and Budget • Orange County Public Works • Riverside County Flood Control and Water Conservation District • RBF Consulting • San Diego Department of Public Works • San Francisco Bay Conservation and Development Commission (BCDC) • Santa Clara Valley Water District • Southern California Integrated GPS Network (SCIGN) • Stoddard and Associates • University of California, San Diego (UCSD) • U.S. Corps of Engineers • U.S. Geological Survey (USGS) • Urban and Regional Information Systems Association (URISA)

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 will be transmitted with RTCM 3.0 data streams starting March 1, 2018.