Patent ID: 7403856
Filing Date: 2008-07-22
Classification: G01C

Abstract:
1. Method for determining in real time whether an air or a land vehicle is exposed to at least one selective source point of interest within a terrain, comprising the steps of: pre-defining a compact size Digital Terrain Model (DTMO) by: a) providing a Digital Terrain Elevation Data (DTED); b) defining at least one selective source point of interest within said DTED; c) for each source point of interest within the DTED, defining a directional fan, said directional fan definition comprises a fan opening angle, a fan azimuth, a maximal range for terrain analysis, and a fan data set having an origin at a corresponding one of said source points; d) evenly dividing each fan opening angle into plurality of angular directions according to a fan angular resolution; e) for each of said fan angular directions, determining all DTED points along said angular direction which have a line of sight with the corresponding fan source point, and discarding all other DTED points in said angular direction which do not have a line of sight with said fan source point; f) for each of said determined DTED points along a same fan angular direction, defining a line of sight starting at the fan source point and:  wherein the collection of all said lines of sight along a same direction form a corresponding directional data set of exposable heights; g) associating all the data sets of exposable heights of a same fan to a corresponding fan data set, all the separate fan data sets form the said DTMO;