A digital terrain model

At first place, the principles and propierties that have been taked into consideration for the building of a digital terrain model in finite differences are showed. The useful data are level contours, profiles, generalizated curves into the terrain surface and isolated points. The data curves are considera-ted as formed by the polygon defined by the series of data points. Under the model considerations is possible to take the error as neglectable; otherwise we must to bring more points to define the curve. The curve definition may be generalizated, including spline techniques and polynomial or trascendet functions. The model basis is a rectangular grid with constant step along the two coordinate axis. The terrain, that is represented by the curves, is sectioned by bundles of parallel planes that goes across the grid nodes, making series of profiles. The model values are obtained from these series. At second place, a practical case and the obtained results, are included. In these results is possible to see the effects and significance of the number of bundles used and the convergence to a solution.