A ground and obstacle collision avoidance technique (GOCAT)

The authors present a novel solution to the problem of providing aircrew with a timely warning of a dangerously close approach to the terrain. An overview of why such a capability is required, the benefits it is expected to provide, and specific requirements that it must fulfil is given. The ground proximity warning techniques which are currently available are reviewed, and the benefits and limitations of each technique are assessed. The GEC Avionics Ground and Obstacle Collision Avoidance Technique (GOCAT), which forms part of the Total Terrain Avionics system, is introduced. The particular advantages of the GOCAT approach, such as the use of a terrain database, are identified, and issues of parameter selection, search area definition, and system limitations are described. The results of a GOCAT simulation are presented to demonstrate the conditions under which a warning is required and generated. The characteristics of a practical implementation for both civil and military applications are discussed