Coherence Parameters Estimation Algorithm for Distributed Coherent Aperture Radar in Low SNR Environment

A method of reducing parameters estimation error by multi-pulse accumulation is proposed to deal with the problem of large error and low coherence performance of distributed coherent aperture radar in low SNR(signal-to-noise ratio) environment. This method uses different coherent accumulation methods for low-speed and high-speed moving targets respectively. For low-speed targets without range migration, discrete Fourier transform is used to achieve multi-pulse coherent accumulation. For high-speed targets, the keystone transform is used to correct the range migration firstly, and then the coherent accumulation is realized by discrete Fourier transform. Then, the peak picking method is used to estimate the coherence parameters. Finally, the coherence parameters estimation process in low SNR environment is given in combination with two cases. The simulation results show that, compared with the method of monopulse signal, this method can obtain higher estimation performance of coherence parameters in low SNR environment. And with the increase of accumulated pulses, the estimation performance of coherence parameters also improves.