Generating lateral guidance image data in a terrain awareness and warning system

A system for generating lateral guidance information in a terrain awareness and warning system of an aircraft, said system comprising:

• a navigation system for acquiring navigation data;
• at least one terrain database comprised of terrain data stored as a plurality of terrain cells of a digital elevation model, wherein such terrain data is comprised of terrain cell location information and at least one value of a terrain cell minimum operating altitude, where each value of a terrain cell minimum operating altitude is associated with a stored parameter representing phase of flight and flight attitude;
• an airport database comprised of airport-related data;
• a lateral guidance processor, electronically coupled to receive navigation data, terrain data, and airport-related data, wherein such processor
• receives navigation data representative of at least aircraft position, a value of aircraft altitude, and projected flight path of an aircraft in flight,
• retrieves airport-related data of the nearest airport from the aircraft position,
• determines a parameter based upon the navigation data and the airport-related data, where such determined parameter represents phase of flight and flight attitude,
• retrieves terrain data representative of one value of a terrain cell minimum operating altitude of each terrain cell located in front of the aircraft, where such retrieval is based upon the determined parameter,
• triggers a first terrain threat if the value of the aircraft altitude is equal to or less than any one value of a terrain cell minimum operating altitude of any retrieved terrain cell located along the projected flight path,
• determines a value of a first minimum left turn angle and a value of a first minimum right turn angle if the first terrain threat is triggered, where the value of each angle is measured from the projected flight path,
• generates first lateral guidance image data based upon the smaller of angles between the first minimum left turn angle and the first minimum right turn angle, wherein such first lateral guidance image data is representative of an image of first lateral guidance information, and
• provides the first lateral guidance image data to a terrain indicating system;
• and
• the terrain indicating system, electronically coupled to receive lateral guidance image data, where such terrain indicating system
• receives the first lateral guidance image data, and
• presents the image of first lateral guidance information represented in the first lateral guidance image data on a visual display unit.