Time delay modeling and compensation of dithered RLG POS with antivibrators and filter

A high rate sampling and digital filter can demodulate and remove the dither noise of RLG caused by mechanical dither. However, the time delay caused by antivibration system and digital filter severely reduce the measurement precision, and become a key problem. To solve the problem, a time delay modeling and compensation method of dithered RLG POS was proposed. An optimized multi-degree uncoupled antivibration system was designed. The dynamic response time delay model based on antivibrator characteristics was established. A linear FIR digital filter was designed to remove dither signal of RLG, the filtering time delay model was accurately established. The RLG POS can accurately measure space–time information by time delay compensation. The experimental results show that the attitude errors are reduced to 0.0028°, 0.0044° and 0.0021° from 0.0033°, 0.0058° and 0.0104°, using proposed time delay compensation method. It contributes to realize high quality image of optical camera without ground control points.

► An optimized multi-degree uncoupled antivibration system was designed.
► The dynamic response time delay model was established.
► A linear phase FIR filter was designed to remove the dither noise of RLG.
► The filtering time delay was accurately modeled.
► RLG POS can accurately measure space–time information by time delay compensation.