Gyrocompassing mode of the attitude and heading reference system

A gyrocompassing mode of the attitude heading reference system was presented. Attitude heading reference system has been composed of inertial measurement unit and navigation computer. Inertial measurement unit consists of triad accelerometers, gyroscopes and a circuit of signal processing. It is received a full expression for the error of gyrocompassing depending from errors of gyroscope, accelerometers and latitude source. It was estimated the errors of gyroscope and accelerometers on the assumption of the required the error of gyrocompassing. Also, it is shown that calibration results are effected to the error of gyrocompassing. It is brought the simulation results of impact any factors such as bias instability of gyroscopes, scale factor instability of gyroscopes, bias instability of accelerometers, scale factor instability of accelerometers, and misalignment of measurement frame axes onto the error of gyrocompassing mode. It is shown that maximum influence on to the error of gyrocom-passing mode has got the bias instability of gyroscopes.