The Implemental Methods of High Velocity Compensation in ISAR Imaging Based on Entropy Minimization

Based on Linear-Frequency-Modulated radar signal model,the influence of high velocity on range profile in ISAR imaging is studied in this paper.In order to decrease the above influence,it puts forwards an algorithm of velocity compensation based on the minimal entropy principle and three implementing methods in application.The simulating test proves the effectiveness of above methods. Furthermore the simulating result shows the ergodic method provides the best precision but the largest calculating quantity.Quicksearch method runs fast while it maintains a low precision.Conic-fit method keeps the advantage of high precision and good real-time performance.The precision of conic-fit method has been analyzed,which provides the foundation for the selection of ergodic step of velocity during the coarse estimation.In the end,the conic-fit method is applied in radar signal processing system.The compensating result of high velocity and its runtime on DSP with real-measured data are given.The result proves that this method is real-time and effective.