As an important advanced technique in the field of Earth observations,Synthetic Aperture Radar(SAR)plays a key role in the study of global environmental change,resources exploration,disaster mitigation,urban environments,and even lunar exploration.However,studies on imaging,image processing,and Earth factor inversions have often been conducted independently for a long time,which significantly limits the application effectiveness of SAR remote sensing due to the lack of an overall integrated design scheme and integrated information processing.Focusing on this SAR application issue,this paper proposes and describes a new SAR data processing methodology–SAR data integrated processing(DIP)oriented on Earth environment factor inversions.The simple definition,typical integrated modes and overall implementation ideas are introduced.Finally,focusing on building information extraction(man-made targets)and sea ice classification(natural targets)applications,three SAR DIP methods and experiments are conducted.Improved results are obtained under the guidance of the SAR DIP framework.Therefore,the SAR DIP theoretical framework and methodology represent a new SAR science application mode that has the capability to improve the SAR remote sensing quantitative application level and promote the development of new theories and methodologies.
Conventional synthetic aperture radar(SAR) systems cannot achieve both highresolution and wide-swath imaging simultaneously.This problem can be mitigated by employing multiple-azimuth-phases(MAPs) technology for spaceborne sliding spotlight SAR systems.However, traditional imaging algorithms have met challenges to process the data accurately, due to range model error, MAPs data reconstruction problem, high-order cross-coupling phase error and variation of Doppler parameters along the azimuth direction.Therefore, an improved imaging algorithm is proposed for solving the above problems.Firstly, a modified hyperbolic range equation(MHRE) is proposed by introducing a cubic term into the traditional hyperbolic range equation(THRE).And two curved orbit correction methods are derived based on the proposed range model.Then, a MAPs sliding spotlight data reconstruction method is introduced, which solves the spectral aliasing problem by a de-rotation operation.Finally, high-order cross-coupling phases and variation of Doppler parameters are analyzed and the corresponding compensation methods are proposed.Simulation results for point-target scene are provided to verify the effectiveness of the proposed algorithm.
