Quality map weighting based multi-baseline least-square phase unwinding method

Abstract

The invention discloses a quality map weighting based multi-baseline least-square phase unwinding method. According to the method, a first-order phase gradient principal value in the winding phase ofa multi-baseline InSAR is calculated, and is extended in mirror symmetry, a second-order phase gradient is calculated, a quality map is used to determine the quality of the winding phase, the windingphase as prior information is used to carry out phase compensation on residual error points in the winding phase, the second-order phase gradient of the winding phase is optimized and weighted on thebasis of the quality map, and multi-baseline least square phase unwinding is carried out to obtain the unwinding phase. Multi-baseline measurement enriches interference phase information of the targetscene, the problem in transferring the phase error of a residual error point in a traditional single-baseline least square phase unwinding algorithm is solved, and the phase unwinding precision is improved.

Description

technical field [0001] The invention belongs to the technical field of radar, in particular to the technical field of phase unwrapping in elevation surveying and mapping of Interferometric Synthetic Aperture Radar (InSAR). Background technique [0002] Interferometric Synthetic Aperture Radar (InSAR) technology was developed in the early 1970s. It combines radio interferometry technology and SAR imaging technology, and can perform all-day and all-weather interferometry on large-area terrain. At the same time, the phase information of the SAR image can be used to extract the three-dimensional information of the surface. The working principle of InSAR is to obtain the SAR image pair of the same scene on the ground through simultaneous observation of two antennas or different passage observations of a single antenna, extract the interferometric phase information of the SAR image, and then combine the geometric relationship of the imaging scene to invert the digital elevation mo...

AI Technical Summary

Problems solved by technology

[0004] In the face of the effects of overlapping and shadowing in the single-baseline InSAR system, and the low accuracy of phase unwrapping caused by undulating terrain, it is necessary to improve the traditional phase unwrapping algorithm. The multi-baseline InSAR phase unwrapping technology is a single-baseline InSAR The expansion of phase unwrapping technology, research on multi-baseline InSAR phase unwrapping algorithm, combined with multiple interferometric phase information with different perspectives for joint processing, can effectively expand the unambiguous elevation range of multi-baseline InSAR systems, and improve phase unwrapping in undulating terrain scenes. Accuracy, which has important application value for multi-baseline InSAR to obtain high-precision 3D information

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