A Fast Method for Time Delay, Doppler Shift and Doppler Rate Estimation

For realizing the rapid estimation of time delay, Doppler shift and Doppler rate of moving targets in passive radar, we present a cross ambiguity function algorithm based on higher order ambiguity function (CAF-HAF). In this algorithm, higher order ambiguity function transforms the nonlinear harmonious signal's estimation to the linear harmonious signal's estimation, then zoom-FFT is used for estimating the frequency portion which the authors are interested about. Therefore, the CAF-HAF algorithm realizes the accurate estimation of the time delay, Doppler shift and Doppler rate of moving target with less computational cost Then the computation cost and the accuracy of the CAF-HAF algorithm are compared with the cross ambiguity function method based on the fractional Fourier transform (CAF-FRFT), showing higher efficiency and being more adaptive for real time signal processing