Analysis of a Triangulated Irregular Network (TIN) Terrain Model for Military Applications

摘要

This report describes a comparative evaluation of two digital terrain models (DTMs) in the context of tactical terrain analysis problems in Marine Corps ground combat operations. The two DTMs are the triangulated irregular network (TIN) model and the uniform rectangular grid (URG) model. The URG model represents terrain by simply encoding the terrain elevations on a uniform grid while the TIN model fits a series of irregular triangular facets to the terrain. The TIN model is a surface-specific model because distinctive surface features, such as peaks, pits, passes, ridgelines, and valley-lines, control the selection of triangular facets. In general, fewer points (triangle vertices) are required to model a given surface with a TIN compared to the URG. Average digital data storage requirements are reduced, although significant digital encoding overhead must be included in the TIN model. The comparative evaluation was performed by selecting several geographical regions of interest and two tactical test problems; the determination of visible ground areas from given observation points, and the determination of accessible ground areas to generic types of vehicles. TIN and URG models of the selected regions were then obtained and separately applied to the solution of the two test problems. Digital data base storage requirements, computer resources used, and computer resource measure was CPU time, and the problem solution performance measure was defined as the areal measure errors in the resulting visibility and slope threshold maps.