ICCP algorithm for underwater terrain matching navigation based on affine correction

ICCP is the most important matching algorithm used in underwater integrated navigation system. Traditional ICCP algorithm can only do rigid transformation (rotation and translation) for the indicated track of underwater vehicle's INS. In order to overcome this problem and improve the accuracy of track matching, the error characteristics of INS are analyzed, and the error model of INS is established. Then a new ICCP algorithm based on affine correction is put forward. The track indicated by INS is transformed according to the ICCP algorithm. The affine parameters are solved with the least squares method. The ICCP matching track is modified by affine transformation. The simulations show that the defects of traditional ICCP algorithm can be avoided by affine correction, and the matching result is better than those of traditional ICCP algorithm, in which the matching error is less than 50% of digital map grid spacing. Meanwhile, the additional time consumed in affine correction is just about one thousandth of that in traditional ICCP algorithm.