Ship's course correction, using directional gyroscope - is by comparison with gyroscopic compass signal at defined time intervals

摘要

The method is for correcting the course value from a directional gyroscope on a ship and involves using a gyroscopic compass (2) whose steering error is corrected by use of a log (7). This is achieved using any log and without requiring a mechanical coupling between the gyroscopes. A navigation gyroscope direction signal, corrected for a known navigation gyroscope drift (16) is compared with a directional output from the gyroscopic compass (2) which is corrected for a known setting error before the steering error correction is applied. A correction value is derived from the comparison discrepancy and applied to the direction signal so as to reduce the discrepancy. The correction value is varied at given time intervals by an amount greater than a random drift, value times the time interval. The sign of the correction is obtained from the comparison result.