Abstract: A method of operating a pulse Doppler radar to increase the probability of detection of an airborne target is shown to consist of transmitting interrogating pulses with a high pulse repetition frequency and processing received signals using any conventional pulse Doppler technique for echo signals having a Doppler shift frequency outside the spectrum of Doppler shift frequencies of clutter and using a DPCA technique at a submultiple of the pulse repetition frequency for echo signals having a Doppler shift frequency within the spectrum of Doppler shift frequencies of clutter.

Abstract: A filter system permits observed data measurements for a multiplicity of radar emitters to be deinterleaved and stored in a buffer memory. A first unit of the system simultaneously compares each one of a series of parameters in the incoming data with respective ranges of parameter values, and produces an indicator of each match made. A second unit of the system assigns an hierarchial order to the indicators from the first unit, and produces from those indicators an ordered sequence of encoded outputs. A third unit of the system is a memory divided into a series of areas equal in number to the number of ranges of parameter values. Each one of the memory areas is addressed by a respective one of the encoded outputs of the second unit. The system allows data corresponding to any one of the radar emitters to be efficiently accessed for further analysis.