Patent ID: 9638785
Date: 2017-05-02
CPC Classifications: B64G,G01S

Claim:
1. A position measurement system for a geostationary artificial satellite, the system comprising: two or more antennas including at least a first antenna and a second antenna that receive, at mutually dissimilar locations, any signal transmitted by a geostationary artificial satellite; a storage device configured to store a reception signal received by each of the antennas, together with a reception time of the reception signal; a distance measurement device configured to measure, by using an antenna for distance measurement, a round-trip time of a radio wave transmitted between said antenna for distance measurement and said geostationary artificial satellite, and to calculate a first distance between said first antenna and said geostationary artificial satellite on the basis of the measured round-trip time, wherein said antenna for distance measurement is said first antenna or an antenna disposed close to said first antenna; and an electronic computer configured to calculate a difference in reception time of a same signal, transmitted at the same point in time to said first antenna and said second antenna by the geostationary artificial satellite, between said first antenna and said second antenna, by performing correlation processing on the reception signal of said first antenna and the reception signal of said second antenna which have been stored in said storage device, to calculate a second distance by multiplying the speed of light and the difference in reception time between said first antenna and said second antenna, and to calculate a distance between said second antenna and said geostationary artificial satellite by adding the first distance to the second distance, wherein the signal used in said correlation processing is a signal in a band which carries information of a satellite broadcasting service or a satellite communications service, wherein the distance measurement device is further configured to measure distances between said geostationary artificial satellite and said antenna for distance measurement a plurality of times at predetermined time intervals to generate a plurality of measured values of the first distance, wherein the electronic computer is further configured to interpolate the plurality of measured values of the first distance so as to acquire the value of the first distance at the same point in time as in the correlation processing on the reception signal of said first antenna and the reception signal of said second antenna, and wherein the distance between said second antenna and said geostationary artificial satellite is used to determine an orbit of said geostationary artificial satellite and carry out orbit control of said geostationary artificial satellite.