Patent ID: 7551990

Claim:
A ground proximity warning system for an aircraft, comprising: a memory for storing one or more of ground or obstacle obstruction information; at least one aircraft sensor system operable to acquire aircraft data; a ground proximity warning computer coupled to the at least one aircraft sensor system that is operable to process the aircraft data to generate one or more of ground and obstacle proximity warning data; and at least one visual display device operable to display terrain elevations and to superimposingly display a visual symbol corresponding to at least one of the ground and obstacle obstructions, wherein the at least one of the computer and the visual display device is controllable to selectively alter an appearance of the visual symbol relative to the terrain elevations, and wherein the at least one of the computer and the visual display device is configured to generate the visual symbol and which corresponds to at least one of the ground and obstacle obstructions having an interior portion and an outer peripheral portion that surrounds the interior portion, and an intermediate portion positioned between the interior portion and the outer peripheral portion.