초록 ▼

A passive system for locating a distant source of radio frequency energy, for example a pulsed radar transmitter, from a portable platform such as a moving aircraft. The disclosed system is non ambiguous in locating ability by way of using time difference of arrival and time difference of arrival-ra

A passive system for locating a distant source of radio frequency energy, for example a pulsed radar transmitter, from a portable platform such as a moving aircraft. The disclosed system is non ambiguous in locating ability by way of using time difference of arrival and time difference of arrival-rate processing of signals received from the distant source. This is in contrast with phase-based locating wherein location ambiguities are inherent. The disclosed system is supported by an included recalibration subsystem enabling practical maintenance of time difference of arrival system algorithm accuracy notwithstanding physical component and signal delay changes attributable to thermal or other environment effects. Maintenance of delay measurements accurate into the tens of picosecond range by this recalibration arrangement are employed to obtain usefully precise energy source locations. Mathematical equation-based disclosures of signal delay algorithms and their recalibration are included.

대표청구항 ▼

[ What is claimed is:] [1.]1. 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 s

[ What is claimed is:] [1.]1. 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.