PROJECT TITLE :

Ambiguity functions, processing gains, and Cramer-Rao bounds for matched illumination radar signals

ABSTRACT:

Ambiguity functions (AFs) are obtained for a radar using matched illumination (MI) transmit signals for the detection of range-spread targets in the presence of muddle. The transmit signals are tailored to focus on and interference spectra and are filtered optimally within the receiver; they're designed to maximize signal-to-interference-and-noise ratio (SINR) power ratios at receiver output. During this paper, expressions for processing gains, spread AFs, and Cramer-Rao bounds on range and Doppler estimates are derived based on chance functions. Here, for extended targets, AFs resulting from using optimal MI constant envelope waveforms obtained via part retrieval techniques demonstrate superior resolution characteristics compared with classic linear frequency-modulated (LFM) signals employing optimal pulse compression. For varied target and clutter spectral models, simulation results show that optimally filtered MI signals give significantly enhanced SINR behavior compared with LFM radar signals. Hopefully, these results set the stage for the induction of MI signaling and receive techniques into conventional radar signal processing and pave the approach for realization of one methodology for achieving cognition in radar systems.