Patent ID: 7123260

Claim:
A method of rendering an image of terrain for display in a cockpit display, the method comprising: forming a set of tiles from raw terrain data, each tile including information concerning the elevation of points on the ground; selecting a subset of tiles to be processed to render the image; sending the subset of tiles to a graphics processor to render an image based on the information in each tile, each tile being associated with a specific area on the ground and including elevation data with respect to the elevation of multiple locations within the specific area; selecting elevation data with respect to some but not all of the multiple locations within the specific area; forming a group of elevation data; selecting representative elevation data from the group; arranging the data in a regular rectangular matrix; selecting a number (n) of data points to be representative data points; forming the group into an n sided polygon within the matrix; selecting a range of data points surrounding each vertex of the polygon such that every data point within the polygon is within the selected range of at least one vertex; assigning to the data point at each vertex the highest value of any data point within the selected range of that vertex; and selecting the vertex data points as the representative data.