| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a ground speed measuring device capable of calculating the ground speed of a car with high accuracy directly, without being affected by a mounting angle. <P>SOLUTION: The ground speed measuring device includes a Doppler sensor 10, a speed detector 20 which calculates the ground speed on the basis of a Doppler beat signal fd output from the Doppler sensor and the angle of antennas 12, 13 provided to the Doppler sensor, a calibrated speed detector 30 which finds a calibrated speed on the basis of a change in level of the signal intensity of the Doppler beat signal obtained when the sensor passes above reflectors arranged at predetermined intervals, and a real angle calculation section 40 which determines the angles of incidence and reflection of the Doppler sensor so that the ground speed calculated by a speed detection means becomes equal to the calibrated speed found by the calibrated speed detection means. When the real angle calculation section finds a real angle on the basis of the calibrated speed, the speed detection means calculates the ground speed on the basis of the found real angle. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
