Feature Selection Criterion for Gravity Matching Navigation

Gravity navigation is a new type of physical field passive navigation, its remarkable characteristic is its precision and reliability are closely related to the selected digital map area. The digital gravity map usually includes the position and the field value information, and is stored in the discrete point form. How to describe the characteristic of the digital map quantitatively and comprehensively is not uniform. In this paper, from the mathematical statistics and the random field theory of the standard deviation, roughness, entropy and relative distance concept is applied to digital gravity map, as a measure of gravity map feature parameters of the calculation methods on the digital map. After the simulation of several matching algorithms in different gravity field, the experience criteria of the map feature region selection is summed up. In order to satisfy the selection criteria, the matching probability is greater than 95 %, and the mean value of the matching error is controlled within 0.3 cell grids. It can be seen that the selection criteria of the feature region can meet the requirements of general engineering applications, and can be used as reference for the actual gravity navigation