Analysis of Echo Signal in Tracking Radar by Time Histogram and Its Experimental Testing

Generally the fractional bandwidth of tracking radar echo signal is lower than an octave. The existence of the target echo signal creates a peak in the histogram of periods at the frequency of the signal. When there is only white noise in the received signal, no distinct peak can be observed in the histogram. However, when both weak echo signal and white noise are coexisted, a peak appears which grows as signal to noise ratio (SNR) increases. This paper presents a simple way based on direct analysis of periods in time domain to distinguish echo signal with low SNR. Comparison of the results from simulation with those from measurement confirms the accuracy of the suggested method.