Construction Of Gravity Map For Navigation Based On ArcGIS And Research On Navigability Analysis

Depend on its passive and autonomous characteristic, the INS(Inertial Navigation System) creates the conditions for the realization of self-hidden locating of underwater vehicle. Therefore,it has been the core-devices of navigation system of underwater vehicle for a long time. However, its position error accumulates over time, so the single INS cannot meet the requirements of long-term and high-precision navigation and positioning. In order to overcome this shortcoming and achieve the goal of readjustment or correction of INS, other hidden information source should be found.The traditional method for correction of the INS error is using the outer information, which may be astronomic, physiographical, wireless or satellite information, but vehicle is required to be close to the surface in these methods when the information is obtained, that will make a great influence on concealment of vehicles. Gravity-aided navigation can solve the problem of the increased error of INS, which has no limit of time, no need to extend out of the water surface and no external radiation. Gravity-aided navigation can correct the error of INS under water, and the long-term covert sail with high accuracy can be come true.Gravity map for navigation is the basic of gravity-aided navigation, but the precision of the map and the character of the area for matching make a great influence on the matching result directly. This paper analyzes the essential request of gravity map for navigation, carry out the gravity data of different period and heterogeneous based on the uniform reference frame using the method of seven- parameters coordinate transformation, in order to achieve consistency use the ellipsoidal height as the datum in gravity observation and in the calculation of gravity corrections and gravity anomalies. Based on these work, we propose a method for navigability analysis of gravity map. In the method, we use the gravitational character parameters of entropy, standard deviation, absolute coarseness, the degree of character abundance, relativity and slope as the guide line, integrate the analytic hierarchy process to propose the concept of the general character parameter which is used to describe the ability of the local gravitation for correcting the error of INS. This paper accomplished simulation employing the ICCP matching algorithms and the results have been analyzed. At the end of the paper, the gravity information management system has been programmed, the process and the approach of the system have been illuminated, the feasibility and maneuverability of the system has been demonstrated from the view of practical application.