Anomalous Behavior of a Marine Gyrocompass

The kinematics of a gyrocompass configuration whereby the binnacle is pendulously mounted inside a set of gimbals, commonly installed on commercial marine vessels, is examined under vessel pitch and roll motions. The gimballing errors of this gyrocompass resulting from such motions are determined as a function of its geometry. It is shown that this design results in significantly greater errors than those resulting from the same configuration with one degree of freedom removed. This anomalous behavior is explained in terms of the compass geometry using approximate analytical techniques, the results of which compare well with experimental full-scale tests.