Method and device for preventing collisions with the ground for an aircraft

Claim 1

In an aerial navigation aid device, the improvement comprising: (a) mass memory means for storing a data base representing at least a substantial part of the terrestrial globe, in a cutout form comprising a grid configuration having at least one level of resolution, each grid being associated with at least one data item representing the maximum altitude inside the grid, said data base having sets of contiguous grids, accessible in accordance with a system of addressing by two horizontal coordinates; (b) input means for receiving status indications representing the position of the aircraft with two horizontal components and the altitude, and its velocity vector, defining the present flight path of the aircraft; (c) a fast access working memory; (d) management means, responsive to said status indications, for accessing said data base to maintain a temporary local map in said fast access working memory, said temporary local map corresponding to the zone wherein the aircraft is traveling, and defining a ground altitude envelope of the terrain in said zone; (e) anti-collision means for determining whether the present flight path matches first and second anti-collision laws in relationship with said ground altitude envelope; and (f) alarm means capable of selectively establishing a first alarm in accordance with a first condition, which includes the fact that said first anti-collision law is violated, and a second alarm in accordance with a second condition, which includes the fact that said second anti-collision law is violated.