Terrain correlation suitability

摘要

Abstract: Terrain-aided navigation (TAN), also referred to as terrain correlation, is a technique that has proven to be highly successful as a navigational aid for autonomous, unmanned guided missiles. Qualitatively speaking, the effectiveness of terrain correlation is a function of signal- to-noise (S/N) ratio. The signal is equivalent to terrain roughness, while the noise is the combination of reference map errors, radar altimeter errors, and INS altitude errors. However, it is not practical to use only a single parameter, such as S/N, to define the suitability of terrain correlation. This paper discusses the shortcomings of the conventional single-parameter approach to the terrain contour matching algorithm (TERCOM) used in cruise missile guidance systems scene selection. A more comprehensive technique is then presented that analyzes the terrain correlation suitability based on a Monte Carlo simulation technique. A figure-of-merit (FOM) for terrain correlation suitability, computed from sample statistics, is introduced and simulation results are provided to illustrate the feasibility of using a multi-parameter FOM technique. The preliminary results indicate that the proposed approach could provide a cost effective enhancement to the TAN-based mission planning process. !6