| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect a GPS electric wave shielding object 15 with high precision and accuracy, even when a GPS antenna 11 is installed on moving routes 14, 14 adjacent to other moving routes 14a, 14a. <P>SOLUTION: This system is equipped with the GPS antenna 11; a GPS transmitter 12 for processing its GPS signal, and outputting a positioning result; a determination device 14 for determining presence/absence of a GPS electric wave shielding object corresponding to success/failure of electric wave reception based on an output S therefrom; a selection means 13c for selecting a GPS satellite 16 used for detection of the GPS electric wave shielding object corresponding to comparison with its azimuth and elevation angle, a reception level, the azimuth and elevation angle of data for selection, and an intensity threshold; a buffer means 13d for holding its selection result for a fixed period; and an azimuth setting means 13b for setting automatically a part of the azimuth among the data for selection based on a traveling direction along the moving routes 14, 14. <P>COPYRIGHT: (C)2009,JPO&INPIT |
