Feature Extraction of Intra-Pulse Modulated LPI Waveforms Using STFT

LPI radar is a class of radar systems that has the ability `to see and not to be seen' i.e. because of certain characteristics that make them nearly invisible to intercept radars. LPI signal, in addition to undetected ability by an unintended receiver, even if intercepted, an intercepted transmission provides no transmitter bearing information to the interceptor. Therefore, LPI waveforms make it tough to be intercepted by means of passive receivers such as radar warning receivers, electronic support (ES) and electronic intelligence receivers, and also help in increasing the detection range of target compared to adversary receiver. So it's needed to intercept the LPI signals embedded within noise so that necessary Electronic Counter Measures (ECM) can be applied. Thus, the primary objective of this paper is to investigate method to counter LPI radar threats because of the specially designed LPI waveforms for that we propose an algorithm to detect and identify the parameters of the LPI signals like frequency, pulse width, PRI, and modulations, using Short time Fourier transform (STFT), even when the signal-to-noise ratio (SNR) is -20dB.