Patent ID: 6255992
Filing Date: 2001-07-03
Classification: G01S

Abstract:
Time difference of arrival long baseline interferometer tethered antenna airborne radio frequency signal emitter locating apparatus comprising the combination of:a search aircraft containing a radio frequency receiver and a first radio frequency antenna and trailing a second radio frequency antenna communicating into said aircraft via a tethering first signal conveying member;said first and second radio frequency antennas communicating a signal from said radio frequency signal emitter to said radio frequency receiver during propagation time difference-segregated events;time difference of arrival signal processing apparatus disposed in said aircraft in communication with an output signal of said radio frequency receiver, said apparatus being responsive to a selected range of arrival time differences of said signal from said radio frequency signal emitter at said first and second radio frequency antennas in generating an angle of arrival output signal;selectively operable signal propagation time delay calibration apparatus electively connectable with said tethering first signal conveying member and with additional signal propagating paths interconnecting said first and second antennas, said radio frequency receiver and said time difference of arrival signal processing apparatus and generating measurement data representative of environment-induced changes in signal propagation delay attending said tethering first signal conveying member and said additional signal propagating paths.