Suppression of Laser Gyroscope Random Error without Dither Noising

The problem of suppressing the random error of a laser gyroscope (LG) based on ring helium-neon laser is considered to improve the accuracy of strapdown inertial navigation systems. The mathematical model for LG primary quadrature signals that includes mechanical rotation of LG body, coupling between counter-propagating optical waves, and additive noise is formed. Three methods to process primary signals, i.e. the reverse pulse counting method (RPC), the method to calculate the instantaneous Sagnac phase (ISP), and the method to calculate the instantaneous Sagnac phase to compensate for dynamic lock-in (ISPC), are studied. The procedure to remove a dither from the counts of LG angular rotation rate using a notch filter is unified. The effect on the registered counts of LG angular rotation rate is determined. The component of LG random error resulting from dither modulation by pseudorandom signal is excluded. The "spurious" Sagnac phase jumps at weak coupling between counter-propagating waves in optical cavity are compensated by means of the ISPC method.