CLEAN-based coherent integration method for high-speed multi-targets detection

摘要

Coherent integration for high-speed multi-targets detection is a challenging task in radar applications. First, range migration (RM) and Doppler frequency migration (DFM) induced by target's complex motions (i.e. high speed, acceleration, etc.) would result in serious integration performance loss. Second, if the scattering intensities of different targets differ significantly, the weak one would be shadowed by the strong target and makes it difficult to achieve the coherent accumulation for weak target. Existing methods either perform poorly or are too computationally expensive for coherent integration of high-speed manoeuvring targets. Two contributions are made towards addressing these limitations. First, a method based on keystone transform, fold factor phase term compensation and generalised dechirp process is proposed to remove the migrations (RM and DFM) and realise the coherent accumulation. Compared with the generalised Radon Fourier transform algorithm, the proposed method can avoid the blind speed sidelobe and has a much lower computational cost. Second, two CLEAN techniques based on sinc-like point spread function (PSF) and modified PSF are presented to eliminate the strong target's effect and highlight the weak ones. By this way, the coherent integration of strong target and weak ones can be achieved iteratively. Several simulations are provided to demonstrate the effectiveness.