Parametrically disciplined operation of a symmetric nearly degenerate mode
vibratory gyroscope is disclosed. A parametrically-disciplined inertial
wave gyroscope having a natural oscillation frequency in the neighborhood
of a sub-harmonic of an external stable clock reference is produced by
driving an electrostatic bias electrode at approximately twice this
sub-harmonic frequency to achieve disciplined frequency and phase
operation of the resonator. A nearly symmetric parametrically-disciplined
inertial wave gyroscope that can oscillate in any transverse direction
and has more than one bias electrostatic electrode that can be
independently driven at twice its oscillation frequency at an amplitude
and phase that disciplines its damping to zero in any vibration
direction. In addition, operation of a parametrically-disciplined
inertial wave gyroscope is taught in which the precession rate of the
driven vibration pattern is digitally disciplined to a prescribed
non-zero reference value.