摘要 |
A gyrocompass has a gimbal (18;218) rotatable about an upright axis (22;222) and a gyro (10;210) rotatably mounted in this gimbal (18;218) about an inner axis (16;216) transverse to the upright axis (22;222). The gyrocompass also includes a level sensor (30,32;230,232) supported by the gimbal (18;218) for providing a level signal signifying the tilt of the upright axis (22;222) from vertical. Also included is a controller (50) connected to the level sensor (30,32;230,232). The controller includes equipment (50) responsive to the level signal for rotating the gimbal (18;218) into an initial position (SP(1)) at which the level signal has a predetermined value. A method employing the foregoing apparatus includes the steps of rotating the gimbal (18;218) until the level sensor (30,32;230,232) indicates the inner axis (16;216) is horizontal. Another step is measuring the torque applied to the gyroscope (10;210) by the horizontal component of rotation of the earth with the spin axis (SA1;SA) of the gyroscope (10;210) rotated about the inner axis (16;216) into a horizontal position. Other steps are rotating the gimbal (18;218) 180 degrees and remeasuring the torque applied to the gyroscope (10;210) by the horizontal component of rotation of the earth with the spin axis (SA1;SA) of the gyroscope (10;210) rotated about the inner axis (16;216) into a horizontal position.
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