An Approach of LPI Radar Signal Detection Based on Visibility Graph

There is an urgent need to address the crucial problems caused by more and more low energy and complex of radar signals in the radar countermeasure field. In 2009, Luque et al. introduced a visibility algorithm to describe time series. In this paper, the visibility graph is applied to radar signal detection. Adjacency matrix of visibility graph is adapted to complex and various electromagnetic environment. On the other hand, differential power spectral density has advantage on low probability of intercept (LPI) radar signal detection. Except for linear frequency modulation (LFM), the proposed approach is efficient to most of LPI modulation types, such as frequency shift keying (FSK), sinusoidal frequency modulation (SFM), binary phase shift keying (BPSK) and LFM-BPSK combined modulation. 1000 Monte Carlo simulation results shows detection probability can reach 92% under -5 dB signal noise ratio (SNR).