Frequency hopping signals analysis based on image processing

An analysis method of frequency hopping (FH) signals based on image processing is proposed in this paper. Firstly the time-frequency spectrum of FH signals is obtained using short time Fourier transform (STFT), secondly the background noise in time-frequency spectrum is removed by contrast stretch, binarization operation and morphological operation, and then time-frequency resolution is improved by morphological thinning algorithm, lastly the parameters of FH signals such as hopping frequencies, hop timing, hop time and hop duration are estimated. Simulation results demonstrate the validity of this method.