A new HPRF mode with highly accurate ranging capability for future airborne radars

A new radar mode has been developed which estimates the target velocity unambiguously and which estimates the range via the time delay of the pulses as in a MPRF mode. To do this, the lengths of the range gates are reduced to approximately the range extent of airborne targets such as fighters. In comparison to common HPRF modes we have now many distinguishable range gates inside the unambiguous range. The resolution of range ambiguities is then done by varying the pulse repetition frequency from burst to burst. The algorithm for the ambiguity resolving considers the fact that during a PRF change, targets can move to the next range gate or can cross one or more adjacent range gates. In addition, the unambiguous velocity measurement is used in an algorithm to compensate the target range migration in order to reduce the false alarm rate