Influence of Orbital Errors on InSAR Data Processing

Orbital state vectors,as an important parameter,which plays a crucial role in the processing of InSAR from the original offset of coarse registration to the accurate generation of the ultimate DEM or deformation measure.Errors in the baseline are caused by the errors in the orbital state vectors,which present as phase errors in the interferogram.The requirement for orbit determination would be less than 1 mm to fully correct the residual interferometric fringes,which is far below the current value around 5~10 cm.The relationship between the residual reference phase and orbit errors was built;and the influence of orbit errors played on elevation errors and deformation errors were analyzed here.And then,the quadratic polynomial approximation was proposed to eliminate residual reference phase from the interferogram,which was verified by the SAR data acquired by ENVISAT satellite over the site of the BAM earthquake.