Radar Waveforms for Supression of Extended Clutter

摘要

Target detection in the clutter from extended fields of scatterers, such as the ground or the sea, is a common problem in radar. Having optimized the system configuration, the designer can further improve radar performance by adapting the transmitted waveform to the particular target environment. This problem is investigated here for detection of a single target in the presence of an extended clutter space. The paper considers the possibility of confining the matched-filter response in delay and Doppler, or ambiguity function, to a narrow strip with arbitrary orientation in the delay-Doppler domain. It is shown that strict confinement of the response is achievable only with waveforms that are unlimited in both time and frequency domain. In practice, efficient use of the frequency band requires that the spectrum be truncated, so that strict confinement of the response is not achievable. One finds that bandwidth can be traded against visibility in clutter. More generally, for a fixed bandwidth, the trade-off is between close-target separability and detectability in the clutter, which are the two tasks that together constitute the resolution problem. The paper illustrates the effects of spectrum truncation for the important case of maximum confinement of the ambiguity function. (Author)