A Study on the Positioning Accuracy against the Satellites Allocation in Kinematic GPS

Abstract

It is pointed out in the Kinematic GPS that the jump of the position and/or deterioration of the accuracy are observed when the satellite number decreases. The authors acquired the cumulative phase numbers of the carrier waves from 7 GPS satellites at both monitor and fixed user stations every 20 seconds. Then they deduced the 2drms's of horizontal distribution of 100 positions in the case of 4 to 7 satellites respectively. The ratio of drms to HDOP value is about 1 cm, which might correspond to the range finding accuracy of the receiver, and almost constant independent of HDOP value and satellite number. It is proved that the reduction of the satellite number brings about the DOP value increase and the accuracy deterioration same as the case of stand-alone GPS and DGPS. This suggests that we need to take care of the DOP value when the satellites are blocked.