The Gravity Matching Area Selection Criteria for Underwater Gravity-Aided Navigation Application Based on the Comprehensive Characteristic Parameter

Matching area selection is a key problem of the gravity matching navigation method, especially for underwater application. The gravitational profile varies when the vehicle gets into the matching area in different directions. Therefore, the matching navigation efficiency is also distinct due to the directionality of matching area. In this study, based on the fractal geometry theory, a characteristic parameter - isotropic coefficient, which can measure the directionality of gravity matching area-is proposed by analyzing the spectrum character of gravity anomaly sequence on 3-D surface. Instead of single parameter, the comprehensive characteristic parameter is built by combining traditional gravity parameters and isotropic coefficient through an analytic hierarchy process for matching area selection. Compared with the traditional method, simulation results prove that the matching area selected by the improved comprehensive characteristic parameter method not only has larger coverage, but also has better directivity.