Low-speed moving target detection of single frame image based on Doppler shift estimation

Abstract

The regular algorithms of target detection and tracking in image domain are very sensitive to the false alarm rate, and so the real time performance is limited by high false alarm rate. In order to reduce the false alarm rate of original target detection and improve real time performance, an algorithm of low-speed moving target detection is proposed in this paper using a single frame image based on Doppler shift estimation. Through transmitting LFM plus a pair signal which is non-sensitive to the Doppler shift, the influence on image by Doppler shift can be ignored. But during the detection in image domain, the Doppler shift of the target echo is used to remove static targets and clutter highlights. The false alarm rate of moving target detection is reduced on the basis of single frame data, and moving target detection is achieved through single the frame image in order to make a better foundation for target tracking later. Firstly, the CFAR determination in image domain is carried out. Then, the Doppler shift of the beamforming signal at the highlights detection is estimated through time-domain broadband beamforming and complex correlation frequency measurement. The static targets and clutter highlights are removed effectively through the single frame image. The validity of the method is verified by the computer simulation and a pool experiment.