Doppler Rate Estimation for Passive Synthetic Aperture Localization Based on Discrete Fractional Fourier Transform

Doppler rate estimation is a critical issue in passive synthetic aperture (PSA) radiation source localization. However, existing Doppler rate estimation algorithms are significantly affected by the residual frequency offset (RFO) between the receiver and emitter. To address this problem, a Doppler rate estimation algorithm for PSA using the discrete fractional Fourier transform (DFRFT) is presented in this paper. The presented algorithm employs a two-step approach, utilizing coarse-to-fine search in the fractional domain, to achieve accurate Doppler rate estimation while also reducing computational complexity. Simulation results show that the proposed algorithm exhibits superior estimation accuracy, and its performance is not affected by the RFO.