Abstract:High accuracy moving target detection is a key technique in the digital radar receiver. The Doppler frequency estimation methods which have been presented can not satisfy the performances of modern digital receivers such as high estimation accuracy, less computation, super low SNR circumstance, etc. In this paper, a high accuracy detection technique of moving target based on double sample rate in low SNR circumstance is proposed, and it includes three main techniques, i.e. unambiguous frequency estimation of sub-sampling signal based on FFT, high accuracy Doppler frequency estimation and radial rate estimation of moving target based on double sample rate.