Fading memory based terrain elevation matching

Terrain elevation matching (TEM) is the concept of using terrain height variations below the aircraft to render a position estimate that is used to bind the error of INS. A new TEM approach using fading memory has been proposed. The basic idea of this approach is using a new correlation function to estimate navigation position. The correlation function is defined by all history measurements with fading memory weight. It is shown via a set of simulations that the method can improve the precision of TEM compare to TERCOM.