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National Geodetic Survey - CORS

image of NGS/CORS data coverage

The National Geodetic Survey (NGS), an office of NOAA's National Ocean Service (NOS),coordinates a network of Continuously Operating Reference Stations (CORS) that provide Global Positioning System (GPS) measurements in support of a broad spectrum of navigation and positioning applications in the U.S. and its territories.

Through a Memorandum of Agreement, NGDC operates the alternate CORS facility in parallel with the main NGS CORS facility in Silver Spring, MD. NGDC also archives CORS data, as per the NOAA/NOS Records Disposition Schedule, section 1602-12.

go to the National Geodetic Survey's CORS main website (external link)

go to the National Geodetic Survey's CORS parallel website (external link)

Further information can be found in the CORS metadata record:

NEWS: CORS at-sampling data available from NOAA's Comprehensive Large Array-Data Stewardship System (CLASS)

NGDC, in coordination with the NGS, has improved user accessibility to historical CORS 'at-sampling-rate' data via NOAA's Comprehensive Large Array-Data Stewardship System (CLASS) infrastructure. In normal operations, NGS decimates CORS GPS data older than 30 days to a 30-second sampling rate in its online holdings, and hands off the at-sampling rate files older than 31 days to the NGDC archive. Previously, a user sent in an email request for at-sampling historical CORS data that was manually fulfilled by NGDC staff. As of June 2013, NGDC has completed migration of the CORS historical data into CLASS. CLASS allows users direct and automated access to the CORS at-sampling-rate archive.

Orders made through the CLASS system may take a day or longer to be fulfilled. Access the CLASS website here: under "Search for Data", under the "Global Navigation Satellite Systems (GNSS)" pull-down menu. You can also go directly to the CORS search. For more information, please contact