New method for extraction of Doppler frequency in scalar miss distance measurement system

It is the key problem to miss distance measurements that how to obtain Doppler frequency from radar echo signals, the measurement accuracy of Doppler frequency affects immediately estimation accuracy of miss distance parameters acquired by non-linear optimize arithmetic. A new method is developed to extract Doppler frequency from the image in this paper. In this method, the radar echo signals, which are received by antenna arrays, are transformed to time-frequency domain through Short Time Fourier Transform (STFT) firstly, then the gray-scale image can be obtained that make the intensity of the spectrum as the gray value, further the centroid estimation method is applied to obtain the extraction of Doppler frequency. Simulation results show that the proposed method can effectively extract the Doppler frequency in the low signal noise ratio and get the exact parameter estimation of scalar miss distance.