| 摘要 |
<p>In a vehicle mounted satellite signal receiving apparatus which adopts a satellite tracking system combining a gyro tracking with a hybrid tracking, there is provided a device which can revise an offset error correction value of a gyro sensor, even if there is a drift in the offset error. In this device, gyro tracking is performed when a reception level is a threshold value Lc or more. The gyro tracking is performed by setting an antenna at an angular velocity omega , which is derived from an equation, omega = - omega G + DELTA omega G, where - omega G is a value resulted from conversion of sign for gyro angular velocity omega G, and DELTA omega G is a prescribed offset error correction value. A reception level declines if the offset error correction value DELTA omega G deviates and therefore an apparent offset error arises in the gyro sensor. When the reception level declines below a threshold value LB, the aforementioned offset error correction value DELTA omega G is revised, basing on the direction of an angular velocity omega S which is used in the hybrid tracking (or step tracking). <IMAGE></p> |
