PRECISION AIRCRAFT GPS POSITIONING USING CORS

For mapping applications that require the highest positioning accuracy possible, a series of Global Positioning System (GPS) base stations must be deployed. This can often be very difficult, especially in inaccessible regions or where the cost of laying out base stations at regular intervals is prohibitive. This article reports on the accuracy that can be obtained by using the Continuously Operating Reference Stations (CORS) of National Geodetic Survey as base stations for airborne GPS positioning. These stations could possibly be used to supplement, back up or even replace the base stations usually deployed for a given project. CORS is a network of over 250 sites containing geodetic quality GPS receivers. Two mapping projects were used to assess the quality, reliability, repeatability and feasibility of using the CORS in airborne mapping missions. In both projects, the CORS in the proximity of the mapping area along with the airborne GPS data were used to analyze the accuracy achieved when using the multiple-base approach. Results show that using CORS for airborne GPS positioning offers great potential for the United States.