Patent ID: 7928908

Claim:
Apparatus for identifying which receiver in a plurality of receivers in known positions in a multilateration system is experiencing a significant group time delay comprising for in a first and subsequent pass: a processor that determines from a first group of receivers a detected position of an aircraft providing a signal source; determines from the detected position of the aircraft and the known positions of a receiver or receivers of a second group a predicted difference in time of arrival of the signal from the aircraft for the second group, using a receiver from the first group as a reference; compares the predicted difference in time of arrival with an actual difference time of arrival at the second group to derive a difference in time of arrival difference; derives a variation in successive difference in time of arrival differences over a segment of a flight path of the aircraft; and determines, in the absence of a significant variation in successive differences between predicted and actual time of arrival differences, and in the presence of a difference between predicted and actual time of arrival differences, that a receiver in the second group is experiencing significant time delay.