PURPOSE: To measure the bearing of an antenna system from the true north highly precisely by obtaining many angular informations with the aid of the interference phenomenon of GPS signals generated in a pair of antenna systems and, at the same time, using the calculated value concerning the direction of a satellite and its elevation and the known interval distance between the antennas.
CONSTITUTION: In an antenna system 1', the antenna element In and Is crosses an antenna system 1 at a right angle and they are placed in an interval of several wavelengths against a GPS signal. A 180° hybrid circuit 2' sends a sum/difference signal of the output from the elements In and Is to GPS receivers 3n and 3n in the same way as a circuit does. The receivers 3n and 3s output digital signals representing its own position, direction and elevation of respective satellites, and signal level through the sum/difference signals from a plurality of satellites and outputs them in the same way as receivers 3e and 3w do. A digital computer 4 calculates the arctangent of the ratio of signal level values, divides the calculated values of the antenna system 1 by the said calculated values, and detects the directions of the respective satellite against the antenna system 1' through applying arctangent calculation. Furthermore, the detected values are calculated to remove the uncertainty therefrom, thereby detecting the antenna bearing from the true north.
HIHARA MAKI
YAMADA YOSHITAKA
| JPS55117977A | 1980-09-10 |
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