Match length estimation in geomagnetic matching system

In geomagnetism aided inertial navigation system,match length is one of the most important parameters.A good choice of match length can help to increase matching probability and precision.In this paper,an analysis on how to choose match length is given.According to the characteristics of magnetic matching,a pointwise-iteration-based method is proposed to estimate the match length,in which an upper limit can be achieved.With the match length,optimal matching result can be obtained at the place where path distortion is minimal,which significantly increases the navigation precision.The proposed algorithm is based on simulation experiments,and the ranges of match length in four directions(up,down,left and right) is obtained by advancing the uncertain domains.Simulation experiments verify the higher performance of this new algorithm.