Terrain Aided Navigation Application for Airborne Platforms

Performances of Inertial Navigation Systems (INS) degrade as time elapses. In order to keep error on navigation informationof airborne platforms which use these kinds of navigation systemsbounded, additional aid systems are used. Global Positioning Satellite Systems (GPSS) are aid systemswhich are widely used. Since their errors are bounded, they are used as aid to INSs within Kalman Filter applications. Although their wide usage, it is very easy to keep GlobalSatellite Positioning Systems out of service locally. In such cases, inertial navigation systems become aidless and their performances degrade with time. When Global Satellite Positioning Systems are unavailable, Terrain Based Positioning Systems (TBPS) are used as aid to inertial systems. TBPSs are based on a positioning method where terrain profiles, which are obtained by using onboard sensors, are compared with a preloaded digital terrain elevation map. In this paper, two different positioning methodsare discussed and evaluated by using the simulation results obtained at 10 different flight paths.