An intelligent differencing GPS algorithm and method for remote sensing

The idea behind differencing GPS (DIGPS), is not where in the world you are that matters, it is where you are with respect to a reference point; this is a variation of differential GPS (DGPS). With DGPS the user is more concerned with where they are in the world with respect to a latitude, longitude and height and they must be within a standard distance of DGPS base station. DIGPS uses two GPS receivers, like DGPS, and a system integration manager. The idea is for the user to know where they are in relationship to a reference GPS receiver set up by the user and navigate with respect to that reference receiver. With both GPS receivers seeing the same signal errors, and if the user is moving, using the Doppler method can be used for determining position and velocity. The inaccuracies normally associated with civilian GPS are ified and the user is not tied to an area where they must be in range of a standard DGPS base station. This could be important tool in the area of remote sensing where sub-cm accuracy is needed with respect to a reference point. This paper examines an intelligent DIGPS system using neural networks and expert systems in conjunction with utilizing the Doppler effect of the carrier wave to build a system that quickly and accurately determines a moving user´s position and speed in relation to a reference point.