Ship Positioning and Radial Velocity Estimation for Spaceborne SAR Based on Energy Center Extraction

Spaceborne synthetic aperture radar (SAR) has a high application value in the observation of ship targets. After the ship is detected, the actual observation position of the moving ship and its motion parameters are worthy of concern, especially for some medium and large size valuable ships. In this paper, we propose a method of extracting the energy center of the ship signal trajectory to locate the ship first. Then according to the difference between the imaging position and the positioning position of the ship, the radial velocity estimation can be calculated. The proposed method does not need to construct a reference data box, and can directly locate the moving ship. The processing of the Gaofen-3 (GF-3) complex data verifies the effectiveness of the proposed method.