THREE-DIMENSIONAL POSITIONING SYSTEM BY GPS RECEIVER USING GPS SATELLITE AND GEOSTATIONARY SATELLITE

摘要

PURPOSE: To enhance the accuracy of a distance measurement by a method wherein the position of a satellite in every moment is monitored, the error of the position of the satellite and the state of the ionosphere and of an atmospheric gas layer are always grasped and a propagation error due to them is corrected. ;CONSTITUTION: A receiver for a large-sized ground station provided with a parabola antenna is installed in a spot whose latitude, longitude and altitude have been decided. The propagation time of radio waves from a satellite and an angle of elevation at the time when the radio waves have arrived are measured. The refractive index of the ionosphere and of an atmospheric gas layer in a propagation route from the satellite up to the receiver is found. Then, the position at every moment of the satellite is measured. The measurements are repeated at certain time intervals, and position data, on the satellite, which corresponds to the found time is transmitted to the whole country. A surveyor puts a GPS receiver in a measuring point, the receives radio waves from a geostationary satellite, he aquires the radio-wave propagation time and the position data on the satellite, and he computes the position of the measuring point. Then, the pulse signal of a GPS satellite is received, a clock error is corrected on the basis of the measured reception time, and the position of the measuring point is decided.;COPYRIGHT: (C)1994,JPO