Comparative Analysis of Algorithms for Initial Alignment of a Strapdown INS with the Help of a Gimballed INS

A technique for initial alignment of a strapdown INS (SINS) for a space launch vehicle (SLV) with the help of information of a gimballed INS mounted on the same vehicle is considered. Three variants of the technique based on employing Kalman filter for processing differences in specific force measured by SINS and gimballed INS accelerometers are discussed. The variants differ in a way of obtaining the residuals. The results of the comparative error analysis of the technique variants are analysed.