Correction study on dithered laser gyro whole cycle sampling demodulation in SINS

In dithered laser gyro strapdown inertial navigation system (LSINS) and under the coning motion circumstance, large attitude drift error occurs when adopting the dithered laser gyro whole cycle sampling demodulation(WCSD) method. With some modification to the WCSD circuit, an effective innovation is introduced to the demodulation technique, and the linear extrapolation for gyro angle increment prediction is deduced. Some simulations are carried out and the results show that the linear plus quadratic extrapolation correction algorithm is perfect and it can decrease WCSD attitude drift error to the error level of the ideal sampling method. The study will help to improve the WCSD application for dithered laser gyro.