Patent ID: 6995689

Claim:
A combined airborne and ground-based system for monitoring an aircraft, comprising: a first airborne means for receiving navigation signals and deriving a position vector therefrom, a second airborne means for receiving an input representative of altitude of the aircraft above ground level, a third airborne means for sampling said position vector and outputting a succession of samples of said position vector, representing successive discrete positions of the aircraft, wherein said third airborne means is responsive to the second airborne means such that the sample rate has a first substantially constant value in the event that the aircraft is at an altitude greater than a predetermined altitude and has a second substantially constant value, greater than the first constant value, in the event that the aircraft is at an altitude less than said predetermined altitude, a fourth airborne means for receiving the succession of samples of the position vector from the third airborne means and generating data packets descriptive of said successive discrete positions of the aircraft, a fifth airborne means for transmitting the data packets, a first ground-based means for receiving the data packets, a second ground-based means for extracting the aircraft position vector samples from the data packets, and a third ground-based means for graphic display of the position vector samples.