Surface ship imaging technology is widely used in military and civilian applications. To resolve the problem of imaging moving target positioning blur on sea surface, this paper proposes a method for estimating the velocity of moving target using velocity synthetic aperture radar (VSAR). Firstly, the paper analyzes the imaging mechanism and constraints of VSAR method and establishes an imaging model based on phased array radar for surface ships. Then, the rate-frequency estimation method of the multi-antenna image domain is used to correct the azimuth offset, and the image moisture algorithm is used to estimate Doppler frequency modulation. Therefore, the adaptive focusing of the target image is completed. Finally, this method is used to simulate and calculate the surface motion ship to realize continuous dynamic imaging of the moving ship. Compared with the traditional single-channel SAR radar and track-interfering radar (ATI) algorithm, the rate-frequency estimation algorithm solves the shortcomings of the azimuth positioning accuracy and improves the positioning performance of the moving target ship under large-area sea conditions.
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