Application of Kalman Filter in UM220 as a Dual System Satellite Positioning and Navigation Unit

Abstract

UM220, a dual system satellite navigation module developed by Unicore Communications Inc., supports single-system satellite positioning as well as combined BD2/GPS system. Kalman filter has been widely applied in PVT estimation, the performance of which is recognized to be superior to that of the classical least square (LSQ). In comparison with the LSQ algorithm used in single-system positioning, Kalman filter based dual system positioning combines closely the two navigation systems by the constraint of temporal dimension, which can access more satellites and measurements form two constellations, and employ the historical information through the application of dynamic model. This paper presents the measurements and the dynamic model of Kalman filter in PVT estimation of dual system, deduces the stochastic model in temporal dimension briefly. It is proved by a large set of tests based on UM220 unit that Kalman filter technology guarantees the excellent precision of positioning and the ability of continuous navigation in severe environment such as urban canyon.