An Effective Method for Ship Imaging of Real Data in Helicopter SAR System

In view of unsteady flying, the helicopter brings about great errors to moving targets imaging, especially the SAR imaging of moving ship. Therefore an effective method is proposed in this paper and it is based on an idea that uses motion compensation and general second-step keystone transform twice and at the same time, finds an isolated point and estimates Doppler parameters in virtue of WVD transform which are used to remove range walk and curvature. What´s more, the detailed proving course of this method is given in this paper. In the end, the SAR imaging of moving ship is acquired in azimuth frequency domain and this paper also analyzes the echo signals of moving targets under different conditions. The simulation result of three moving point-targets and the imaging result of real ship data have confirmed this method