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Continuously Operating Reference Station Program, National Geodetic Survey

The National Spatial Reference System "Takes Flight": 1987 – 2007, NOAA 200th Anniversary Web Site

Celebrating 15 Years of the CORS Program

CORS station

To help scientists and others monitor our ever changing planet, NOAA manages a network of advanced Global Positioning System receivers know as Continuously Operating Reference Stations (CORS) to provide highly accurate positioning information.

This February, the National Geodetic Survey (NGS) is celebrating the 15th anniversary of the Continuously Operating Reference Station (CORS) program.

The CORS program got its humble beginning in February 1994 with the installation of a Global Positioning System (GPS) receiver on the campus of the National Institute of Standards and Technology in Gaithersburg, Maryland.  This CORS site has remained operational for all 15 years, with a few upgrades over time. 

Today, this one site is part of a CORS network that includes more than 1,350 independently owned, operated, and maintained stations. There are more than 200 partners in the CORS network representing federal, state, and local governments, as well as academic and private organizations.

The CORS program provides Global Navigation Satellite System data to support three-dimensional positioning, meteorology, space weather, and geophysical applications throughout the United States, its territories, and several foreign countries. 

Each station in the CORS network is a stationary, permanent GPS receiver that collects satellite signals around the clock. NGS uses these data to determine precise three-dimensional positional coordinates for the CORS sites. Also, NGS makes these data publicly available via the Internet. With freely available GPS data from over a thousand CORS sites, surveyors and others need only deploy one GPS receiver to position points with accuracies to within a fraction of an inch in all three dimensions.

The CORS network is an integral part of the National Spatial Reference System which is the foundation for latitude, longitude, and elevation measurements used by all civilian federal agencies and the public.  The network is expected to continue to grow at a rate of about 200 stations per year in the next few years.