Study Of Airborne Synthetic Aperture Radar Motion Error Analysis And Motion Compensation Based On Data

Synthetic aperture radar(SAR) enhances radar's information acquisition capabilityand information awareness ability by obtaining high resolution imageries. Now,SARhas been widely used in airborne radar system as a new function of modern radar.Especially for litter airborne SAR platform flying at middle and low height, Its flightpath and motion attitudes are hardly controlled in the influence of airflow during theperiod of recording data. It has important application value and academic value doingfor research on motion error analysis and motion compensation.Studying the technology of SAR is usually based on SAR imaging. They arenecessary to SAR imaging comprehending the theory of SAR and applying SARimaging algorithm. The theory of SAR is introduced from physical concept and SARimaging processing using simulated data. Then common SAR imaging algorithms arediscussed.Motion compensation is one of the key steps in the signal processing of a SARsystem. Motion compensation is based on measurment instrument or the SAR real data.The latter is particularly studied in this dissertation. It is helpful to fulfill motioncompensation analyzing motion error through raw data. Firstly, we set up a motionerror model and propose a method to analyze the motion error based on the returns ofstrong scatterers. Then different raw data are analyzed, and the rules of motion errorare obtained. Based on the analysis, the appropriate compensation policies areproposed. According to the results of motion error analysis, the motion compensationapproaches basing on the estimation of Doppler instantaneous chirp rate and phasegradient autofocus (PGA) are discussed in detail.