Method for fusion unwrapping of spaceborne InSAR long and short baselines

Abstract

The present invention discloses a method for fusion unwrapping of spaceborne InSAR long and short baselines. The method comprises: employing a spaceborne InSAR system interference processing flow to respectively perform inversion of digital elevation models (DEM) of a long baseline and a short baseline; employing three-dimensional coordinates of ground points corresponding to each pixel point in the images of the long baseline and the short baseline, combining data such as satellite parameters, offset and the like, calculating a vertical baseline and an effective baseline respectively corresponding to the images of the long baseline and the short baseline, selecting an appropriate reference ground, and calculating the long baseline interferometric phase and the short baseline interferometric phase corresponding to the reference plane; and finally, taking correlation coefficients, reference plane phases, baselines and the like obtained before as auxiliary data, employing a maximum likelihood method, and performing fusion processing of the long baseline phase data and the short baseline phase data so as to obtain a long baselined unwrapping phase with higher precision. The method for fusion and unwrapping of the spaceborne InSAR long and short baselines is used in the multi-baseline interference processing, the maximum likelihood method is employed to fuse the long and short baseline unwrapping phases to obtain high-quality DEM; and the method for fusion and unwrapping of the spaceborne InSAR long and short baselines can be also used for fusion processing of data such as interferometric phase and elevation, etc.

Description

technical field [0001] The invention relates to the field of space-borne synthetic aperture radar interference processing, in particular to a long and short baseline image fusion and unwrapping method for interferometric synthetic aperture radar (InSAR for short). Background technique [0002] InSAR measurement is a very important space-to-ground measurement technology. This remote sensing technology obtains multiple SAR images at different observation positions, and calculates two (multiple) SAR complex images corresponding to the same target point on the ground. The phase difference is used to obtain the interferometric phase data, and then the interferometric phase is phase-unwrapped, which is used as an information source to obtain surface elevation information. Therefore, phase unwrapping is an extremely important link, which will directly affect the quality of Gaocheng products. In order to obtain more accurate elevation information, multi-baseline data fusion can be ...

AI Technical Summary

Problems solved by technology

Although the space-borne InSAR system has a high measurement sensitivity under a long baseline, its interference fringes are dense, and it is difficult to perform phase unwrapping; under a short baseline, due to the high ambiguity height, the measurement accuracy is relatively low. However, the accuracy of interferometric phase unwrapping is higher than that of long baseline

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