THREE-DIMENSIONAL ACCURATE LOCATING SYSTEM FOR OBSERVATION POINT OR SATELLITE THROUGH RELATIVE MEASUREMENT

摘要

PURPOSE: To measure three-dimensional positions at high accuracy kinematically by dividing a specific sky area above observation points into plane layers each of which is parallel to a plane passing the observation points, and calculating the radio refractive index of each parallel plane layer. ;CONSTITUTION: The time required for an electric wave to propagate between a satellite and an observation point is measured and the vertical distance between the satellite and the observation point is measured. The cosine of the angle at which the electric wave reflected from the satellite at that time impinges on the boundary between the layer through which radio waves rectilinearly propagate and the ionosphere is calculated at desired accuracy. Such a set of data are synchronized with orbit information transmitted via geostationary satellites and for each satellite 1000 sets of the region going up to 1000 km from each observation point are calculated to correspond to the observation points. Simultaneous linear equations of 100 degrees are thus provided at each satellite and solved to calculate at desired accuracy the radio refractive index of each of parallel plane layers near which radio waves connecting the satellites to the observation points are transmitted. The position of each observation point relative to the satellites is thus determined. Since the position of each satellite at a given time is determined, the three-dimensional position of each observation point is determined.;COPYRIGHT: (C)1994,JPO&Japio