The Research On Matching Algorithm Of Terrain Aided Navigation System

Terrain-aided navigation (TAN) is a kind of all-weather low-altitude navigation technology, which provide navigation information by the use of terrain height characteristics. Terrain aided navigation is an important military navigation technology in the world today, because of its high precision, completely independent character, it is also one of the important direction of modern integrated navigation. TAN has many important applications in navigation of precision-strike weapons. It is very important method of integrated navigation at present. This paper started with aided navigation technology, contained an introduction of several common terrain elevation matching systems based on inertial navigation systems, and a brief summary of the backgrounds of their developments, their principles and applications.Matching algorithm is the most important and widely-studied part of terrairr-aided navigation system. The research is focused on not only its principle and procedure but also the influence of application conditions on matching precision. The paper studied terrain elevation matching algorithms as the emphasis, showed analyses of their principles and tested on simulation datum. Four algorithms had been selected for programming:Mean Absolute Difference algorithm, Mean Square Difference algorithm, the Sandia Inertial Terrain Aided Navigation algorithm (the Extended Kalman Filter as the core) and the Terrain Elevation Matching algorithm based on the Bayesian Estimation. With results of algorithms calculating different datum of Digital Elevation Models, the paper presented accuracy comparisons of terrain elevation matching algorithms, and discussed their applicability. This paper’s conclusions can be used as references to choose the proper algorithm for systems.