| 摘要 |
PURPOSE:To measure a position with high accuracy, by determining a satellite receiving sequence by discriminating the number of the common satellites of a V (vertical) DOP (dilution of precision) optimum satellite group and an H (horizontal) DOP opti mum satellite group. CONSTITUTION:The receiving signal from an antenna 1 is converted in its frequency by a frequency converter 2 and the correlation of the receiving signal and a PN code internally generated is taken in a dummy distance measuring device 3. The correlation output signal from the measuring device 3 is inputted to a position measuring operator 5 through a track data demodulator 4 or directly to operate the altitude of the operator's own car and the altitude thereof is displayed on a display device 6. Next, VDOP and HDOP optimum satellite group selectors 7, 8 select a satellite group wherein both of VDOP and HDOP become optimum on the basis of the GPS (global positioning system) satellite data stored in the operator 5. A receiving satellite change-over device 9 discriminates the common satellite group of the VDOP and HDOP optimum satellite groups to determine a satellite receiving sequence. A receiving control operator 10 respectively imparts a PN code selection signal, a code phase and a carrier wave frequency data to the measuring device 3 and the demodulator 4. |
