Block Adjustment of Orientation Parameters and Interferometric Parameters Using Very High-Resolution SAR Data for DSM Mapping

Block adjustment technology can effectively correct the interferometric parameter errors acquired from Interferometric Synthetic Aperture Radar (InSAR) system. It can reduce the number of required ground control points and improve the accuracy of the generated digital elevation model, making it's an effective means for obtaining three-dimensional information from large-scale terrain information. However, the currently used adjustment models usually only involve surface elevation parameters, which means that the accuracy of the terrain planimetric information entirely relies on the Position and Orientation System (POS) parameters. This may lead to the inaccurate planimetric to be a fundamental weakness which hinder the practical application of this technology. To solve these problems, this paper proposed a DSM (digital surface model) mapping scheme by using very high-resolution synthetic aperture radar (SAR) data that combines the block adjustments of orientation and interferometric parameters. Firstly, the interferometric and orientation parameters are obtained separately by using InSAR and SAR block adjustment techniques. After optimizing the model parameter accuracy, the elevation information obtained from the interferometric parameters is incorporated into the SAR positioning model to acquire the three-dimensional information of the area accurately. Experimental processing was conducted using 23 pairs of airborne InSAR data from two strips in the Weinan area of China. The experimental results demonstrate that the proposed scheme can improve the elevation accuracy by approximately 20%.