Originally designated the NAVSTAR (Navigation System with Timing And Ranging), the Global Positioning System (GPS) was developed by the US Department of Defense to provide all-weather round-the-clock navigation
capabilities for military ground, sea, and air forces (replacing the ďTransitĒ system of the early 1960's).
The Continuously Operating Reference Stations (CORS)
network is a set of hundreds of stationary, permanently operating GPS receivers
throughout the United States. CORS stations continuously receive GPS radio
signals, and integrate their positional data into the National Spatial Reference System. This data is then distributed over the Internet
. After logging onto the CORS Web site, users can determine the accuracy of their coordinates down to the centimeter.
The National Geodetic Survey's Continuously Operating Reference Station (CORS) Web Site. CORS - Continuously Operating Reference Stations
This is the official Web site of NGS's continuously operating reference stations (CORS). Surveyors, geographic information system (GIS) professionals, engineers, scientists, and others use data from the CORS system to assure horizontal and vertical positioning accuracies within a few centimeters.
A central feature of this Web site is a "dynamic" map of the United States and its territories. The different symbols and colors on the map indicate the locations and sampling rates of hundreds of CORS stations in the United States' network. By selecting and "clicking" on an area of the map you can "zoom" into a region where a CORS receiver is located. By selecting and "clicking" on a specific receiver, you can view a detailed area map showing the receiver's exact location, see photographs of the receiver, and view coordinate data that the receiver is collecting from Global Positioning System satellites in real time.
When a specific receiver has been selected, you can obtain different kinds of information about it from the menu on the left hand side of the Web page. Just select the information you would like to see and then "click" the submit button.
CORS - Continuously Operating Reference Stations