A prototype hybrid terrain database is being developed in conjunction with other databases and with hardware and software that constitute subsystems of aerospace cockpit display systems (known in the art as synthetic vision systems) that generate images to increase pilots’ situation awareness and eliminate poor visibility as a cause of aviation accidents. The basic idea is to provide a clear view of the world around an aircraft by displaying computer generated imagery derived from an onboard database of terrain, obstacle, and airport information.

The hybrid terrain database, which could constitute all or part of such an onboard database, can be characterized as an accurate model of terrain and obstacles of interest to a pilot. The hybrid terrain database contains (1) imagery derived from conventional aerial photographs of a terrain area of interest, (2) a digital elevation map of the terrain area of interest, and, optionally, (3) information on the area of interest from other databases.

The hybrid terrain database is used to generate synthetic terrain imagery (see figure) in a hybrid textured format, which is best described in terms of the process by which the synthetic imagery is generated: The hybrid texture is created from monochromatic aerial photographs of the affected terrain area merged with color coded elevation-based terrain imagery (see figure). The process involves coloring the monochromatic aerial photographs of the affected area on the basis of altitude and draping the resulting elevation-colored photographs onto the digital elevation model of the terrain.

This work was done by Trey Arthur of Langley Research Center. For further information, access the Technical Support Package (TSP) free on-line at www.techbriefs.com/tsp under the Information Sciences category. LAR-16898-1