| 摘要 |
PURPOSE:To increase the frequency of position measurement by GPS navigation method by selecting a GPS satellite used for present position calculation based on the azimuth of car proceeding and the data of region where wave from a sattelite is shielded. CONSTITUTION:In a memory 1c, a shield region for azimuth and angle is set according to an antenna fixing position at the fixing time. A controller 6 calculates the present position of a car 8 from the proceeding azimuth and running distance, and simultaneously a satellite selector 1b identifies the shielded region of wave from satellites 3a to 3f by using the data regarding the wave shielding region read out of the memory 1c and the car proceeding azimuth received from the controller 6, recognizes the positions of satellites 3a to 3f by the satellite information received through an antenna 2 and a CPS receiver processor 1a, compares the positions of the satellites 3a to 3f with the identified wave shielding region and selects a satellite out of the shielding region as an available one for position measurement. |
