Two-dimensional unwrapping method based on time sequence differential interference synthetic aperture radar data

Abstract

The invention provides a two-dimensional unwrapping method based on time sequence differential interference synthetic aperture radar data. The method comprises the following steps: generating a time sequence SAR image data set; registering the time sequence SAR images; extracting high-coherence points of the registered time sequence SAR image data set; carrying out differential interference processing on the SAR images after time sequence registration; performing nearest neighbor interpolation on the interferometric phase diagram; performing phase unwrapping on each interpolation differentialinterferometric phase diagram; and extracting a high-coherence point unwrapping result. According to the method, phase data on high-coherence points in the differential interferogram are utilized instead of all phases, interference of points with large phase errors on the whole unwrapping process is eliminated, and therefore the phase unwrapping errors are reduced; sparse grid data and regular grid data are associated by adopting a nearest neighbor interpolation method, so that an original regular grid unwrapping method is suitable for sparse grids, only an original data processing flow needsto be slightly changed, and the method has a relatively high integration level.

Description

technical field [0001] The present application relates to the technical field of radar signal processing technology, in particular to a two-dimensional unwrapping method based on time-series differential interferometric synthetic aperture radar data. Background technique [0002] Differential Interferometry Synthetic Aperture Radar (DInSAR) is a microwave remote sensing technology with great potential. It can obtain centimeter-level or even millimeter-level surface deformation in deformation detection, and has been successfully applied, but its measurement accuracy is still limited by many. Constraints of factors: such as image registration error, complex terrain or decoherence noise in areas with more vegetation coverage, orbital error, phase unwrapping error in complex areas, atmospheric delay error, and terrain phase residuals that are not allowed to be introduced by external digital elevation models. Poor wait. Among these errors, since the phase unwrapping error is sub...

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Problems solved by technology

[0005] This application provides a two-dimensional unwrapping method based on time-series differential interferometric synthetic aperture radar data, combining the advantages of traditional grid phase unwrapping and time-series differential interferometry The high coherence point characteristics in the middle solve the difficulty that the traditional phase unwrapping method is not suitable for data with large interferometric phase errors

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