Method for GPS Measurement Prediction using Inertial Sensor under the Weak Signal Environments(full paper)

Abstract

Unlike conventional differential GPS, precise point positioning requires no base receiver station, nor does measurement differencing need to be carried out. Instead, not only precise satellite orbit and clock information but also effects such as solid earth tides, satellite phase windup, troposphere delay, and ionosphere delay and satellite antenna offsets are corrected. When vessels navigate along the coast or inland waterways, satellite signals are weaken by many bridges and facilities. Under the weak signal environments, it is impossible for receivers to perform carrier phase based precise positioning, and it is difficult to search and maintain the ambiguity of the carrier phase. Since measurement noise power increases in a weak signal environments and satellite DOP(Dilution Of Precision) is poor, it is necessary to develop a robust precise positioning system that can be operated under the weak signal environments. This paper proposes method for GPS measurement estimation using inertial sensor under the weak signal environments. Continuous measurements are prerequisite for maintenance of robust precise positioning performance. Although measurements are not received continuously under the weak signal environments, it can be predicted using IGS information, inertial sensor, troposphere model and carrier phase statistic. Code and carrier phase measurements include geometric range, receivers such as solid earth tides, satellite phase windup, troposphere delay, and ionosphere delay and satellite antenna offsets are corrected. When vessels navigate along the coast or inland waterways, satellite signals are weaken by many bridges and facilities. Under the weak signal environments, it is impossible for receivers to perform carrier phase based precise positioning, and it is difficult to search and maintain the ambiguity of the carrier phase. Since measurement noise power increases in a weak signal environments and satellite DOP(Dilu