Coherent Estimation of Range Difference and Range Rate Difference for Unknown Frequency Hopping Signals

This paper addresses the estimation problem of range difference and range rate difference for unknown frequency hopping signals in passive emitter localization, considering the range migration (RM) of the high-speed moving target within the observation time. A coherent estimation algorithm based on the scaled Fourier transform is proposed. This method can effectively remove the RM and random phase effects. The whole estimation process can be fast implemented without any searching operation. Numerical experiments demonstrate that the estimation performance of proposed algorithm is superior to existing algorithms, and comparable to the maximum likelihood estimator.