Application of two methods for alignment of FOG INS

Initial alignment is of vital importance to inertial navigation systems (INS). There are mailnly two popular methods in self-alignment, which are traditional gyrocompassing alignment algorithm and kalman filter algorithm. After giving the basic principle of the two, we do some simulation and test in use of INS based fiber opitic gyroscope (FOG). The simulation and real experiment show that kalman filter is better than gyrocompassing in level alignment, however, the accuracy of azimuth misalignment angle estimation is lower. The real data test result is as similar as simulation. This provides a useful reference for design alignment algorithm for FOG INS.