The study of north-finder based on rate biased RLG

Abstract

Rated biased RLG is used in the north-finder based on a continuous rotation platform. Along with the rotating platform, the input axis of RLG relative to the earth rotation rate vector periodically changes. In this way, the measurement error of RLG is modulated in every direction. The cross-correlation analysis method is used for getting the azimuth angle. Considering the periodicity of gyro outputs, a digital filter is designed to decrease the influence of quantization error of RLG and some other wideband error sources. Experiment results show that the “cross-correlation analysis + filter” method can markedly increase the precision of the north-finder.