Use of bistatic radar system for determining distance between airborne aircraft

摘要

A bistatic passive radar system and method for airborne use in a first aircraft in conjunction with a host transmitter located in a second aircraft that may be at a different altitude than the first aircraft, characterized by a system and method for determining the distance between the aircraft. The system for determining the distance between the aircraft includes a system for receiving radar signals from the host transmitter directly and via reflection from a selected ground target located between the two aircraft; a system coupled to the receiver for determining the apparent range R.sub.a from the host transmitter on the second aircraft to the receiver on the first aircraft in response to receipt of the radar signals; a device on the first aircraft for determining the altitude H of the first aircraft; a device on the first aircraft for determining the angle &thgr; with respect to vertical at which the radar signals are received directly from the host transmitter; a device on the first aircraft for determining the angle &phgr; with respect to vertical at which the reflected radar signals from the ground are received; and a computer system on the first aircraft for computing the distance D between the two aircraft from the determined values of R. sub.a, H, &thgr; and &phgr;. The system further includes an alphanumeric display device coupled to the computer system for providing an alphanumeric readout of the computer value of the distance D between the aircraft.