Novel two position ground alignment technique for Strapdown Inertial Navigation System

The paper describes a novel two position alignment procedure on ground for Strapdown Inertial Navigation System. The method makes use of accelerometers and gyroscopes measurements from a standalone INS without any external aiding to obtain higher accuracy of heading angle. This technique mitigates the effect of down-gyroscope bias by solving simultaneous equations for the determination of azimuth. The accuracy is further improved by implementing a linear search to correct the azimuth dithered by the presence of gyroscope bias. The supporting simulation and experimental results are presented. The algorithm can be used in launch vehicle applications where there is a need for higher accuracy of azimuth prior to launch.