Improvement of the positioning accuracy of a software-based GPS receiver using a 32-bit embedded microprocessor

This paper describes the improvement of the positioning accuracy of a GPS receiver, using software to apply the GPS to compact, hand-held devices. Differential GPS (DGPS) with a software FM demodulator, and a modified Kalman filter is proposed and applied to a GPS receiver. The positioning accuracy is, 35 m with a standalone GPS, 9 m with DGPS and 15 m with a Kalman filter. With both methods, the positioning accuracy is drastically improved to 2 m.