The Research On Radar Imaging Method For Ship On The Dynamic Ocean Surface

China has nearly 18000 kilometers sea line and approximate 300 million square kilometers exclusive economic zero.Thus the right and interests of ocean have a great strategy meaning for our nation.When developing,using and maintaining the ocean related event,motion states of ship targets,as the main transporting method and the strategy vehicle,not only involve the corresponding economic interest but also relate to the territorial sovereignty and coast defense security.In order to detect the ship target among the oceanic radar clutter and the wave movement,the electromagnetic scattering of dynamic ocean and ship is needed to be study,designing a proper dynamic ocean ship simulator.Moreover,due to the movement of ship,the radar image will bur.Thus the motion compensation of radar image is also a great study topic in this problem.In this thesis,combining the radar imaging theory,the ocean modeling theory and electromagnetic scattering method,a dynamic ocean simulator which can exactly reflect the ocean influence on the ship target is devised.And based on that simulator,this thesis focuses on the study of adaptive joint time frequency(AJTF),a motion compensation method,its optimal algorithm and performance analysis.Conventional dynamic ocean and ship simulator use the four-path assumption to simplify the interaction between the ocean and the ship,which incurs the non-comprehensive analysis.Focusing on this problem,this thesis study the shooting-and-bouncing electromagnetic algorithm and ship movement theory on ocean,designing a novel dynamic ocean ship simulator.This simulator can achieve electric-large simulation for 400 × 400 m and could simulate the wind-driven ocean ship model.Considering the computationconsumption,the graphic processing unit is utilized for both electromagnetic scattering and radar imaging.Comparing the old simulator,it dramatically speeds up the calculation.Based on proposed simulator,this thesis also study the radar image motion compensation method for dynamic ocean ship.The AJTF is firstly introduced with analysis of its improved estimation algorithm,particle searching optimization and polynomial transform,proving its validity.Furthermore,a novel AJTF based on neural network is addressed,and study mainly on its compensation quality,stability and efficiency.By simulation,proposed method successfully compensated the burring image.And under given image quality,the method is stable and without obvious deterioration with decreasing signal-to-noise ratio.In the end,comparing to the conventional AJTF estimation method,particle searching optimization and polynomial transform,it has 407 and 2.07 times speeding up,respectively.