Parameter Estimation of Chirp Signal using STFT

This paper suggested a technique called short time Fourier transform (STFT) for the parameter estimation of chirp signal in intercept SONAR. STFT is one of the time-frequency method and it is a valuable tool for estimating the parameters like start frequency, end frequency, band width, pulse width and chirp rate of chirp signal. Thus for doing parameter estimation, consider two scenarios: pure chirp signal and chirp signal embedded in noise. Generally the parameter estimation in intercept sonar requires a minimal frequency resolution of 250Hz, but achieved a frequency resolution of 50Hz by using STFT technique which is much higher than the required frequency resolution. Also the maximum tolerable error limit in pulse width estimation is ± 40ms.The simulation results show that in both scenarios, we achieved a lesser error value in pulse width estimation .STFT technique is found to be an efficient tool for the parameter estimation of noisy chirp signal with SNR varies from 0dB to -10dB.