Slow-Moving Target Detection Performance of an LPI APCN Waveform in Surveillance Applications

The Advanced Pulse Compression Noise (APCN) waveform is a widespread radar signal that combines the Low Probability of Intercept (LPI) characteristic of a random wave- form with the Doppler tolerance feature of a Linear Frequency Modulation signal. Correctly choosing the stochastic properties of the signal’s random component enables the enhancement of the APCN LPI characteristic, always at the expense of a deterioration concerning its Doppler tolerance. In addition to the earlier mentioned dichotomy, an untapped drawback arises when using the APCN waveform in surveillance: the difficulty in detecting slow-moving targets such as in sea and ground applications. The contribution of the noisy component to the matched filter output can lead to ambiguities in the detection and, therefore, the possibility of false targets. Within this context, this work presents closed-form expressions of the narrowband ambiguity function of APCN signals, enabling a proper analysis of the slow target detection issue. An additional processing step is then proposed as an alternative to prevent this undesired effect.