How do terrain contour matching systems function?

Terrain contour matching systems function by using radar technology to compare the aircraft's surroundings with an onboard digital map of terrain features. This process involves the system sending out radar signals that bounce off the ground and then measuring the time it takes for those signals to return. By analyzing the returned data, the system can determine the elevation and contour of the terrain beneath the aircraft.

This measurement is then matched against the pre-stored map data, enabling the aircraft to identify its position relative to known topographical features. Such systems enhance navigation and situational awareness, particularly in low-altitude flight operations where visibility may be limited. The integration of radar allows for reliable performance in various weather conditions and enhances safety by providing a precise reference to the terrain.

The other methods listed do not accurately describe how terrain contour matching systems operate. They do not rely solely on satellite signals, human navigation, or infrared sensors, which limits their effectiveness or functionality in the context of terrain contour matching.