| 摘要 |
PURPOSE:To perform precise position measurement by reading an optimum arrangement satellite number out of a memory and selecting a satellite which is optimum in current position, altitude, and time immediately. CONSTITUTION:The optimum arrangement satellite number is calculated previously on the basis of parameters of a position, altitude, and time, and the result is stored in a memory 13 for the optimum arrangement satellite number. A satellite radio wave received by an antenna 10 is processed by a reception arithmetic processing part 11 to measure the current position, altitude, and time of a vehicle. Then, the satellite number which is measurable with the optimum measurement precision at the current position, altitude, and time is read out of the memory 13 and compared with a satellite number which is received currently to change satellites when necessary, thereby measuring the position with the best measurement precision. |
