InSAR atmospheric delay correction method assisted by GNSS chromatography technology

Abstract

The invention provides an InSAR atmospheric delay correction method assisted by a GNSS chromatography technology. The InSAR atmospheric delay correction method comprises the following steps of S10, reconstructing a three-dimensional total refractive index field of atmospheric water vapor in a research area, S20, taking the radiosonde data of the research area as a reference value, carrying out the precision evaluation of the chromatography result, and carrying out the step S30 if the precision meets the requirements, S30, obtaining a refined three-dimensional total refractive index field by using a spatial interpolation algorithm, S40, estimating the oblique path total delay amount of the SAR signals in the main image and the auxiliary image by using a Ray-tracing algorithm, S50, generating an atmospheric delay phase diagram of the interferometric SAR image, S60, generating an SAR unwrapping interferometric phase diagram, and S70, obtaining an InSAR phase diagram of atmospheric correction. According to the InSAR atmospheric delay correction method assisted by a GNSS chromatography technology, the GNSS chromatography technology and the spatial interpolation algorithm are utilized to acquire the refined three-dimensional total refractive index field, and the Ray-tracing algorithm is combined to accurately estimate the oblique path atmospheric delay amount of the three-dimensional SAR signal, so that the inversion precision of the atmospheric delay phase of the SAR image is improved, and high-precision correction of InSAR atmospheric delay is realized.

Description

technical field [0001] The invention relates to the field of InSAR atmospheric delay correction, in particular to an InSAR atmospheric delay correction method assisted by GNSS tomographic technology. Background technique [0002] Synthetic aperture radar interferometry (Interferometric Synthetic Aperture Radar, InSAR), as a space geodetic method with great application value in recent years, has the advantages of high precision, wide range, and high resolution. And glacier movement monitoring and other fields have broad application prospects. In actual measurement, SAR satellite signals are affected by atmospheric water vapor, causing propagation path delay, that is, atmospheric delay effect, which not only reduces the measurement accuracy of InSAR technology, but also limits the application range of InSAR technology to a certain extent. [0003] Atmospheric delay in InSAR measurement refers to the difference in the delay of the propagation path caused by atmospheric refract...

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Problems solved by technology

[0005] In order to solve the above problems, the present invention provides an InSAR atmospheric delay correction method assisted by GNSS tomographic technology, which uses all-weather GNSS data to provide a three-dimensional total refractive index field with high temporal and spatial resolution in real time, which is conducive to obtaining atmospheric data synchronized with SAR images. The delay phase map solves the problem of inconsistency in the observation time of the traditional method; the spatial interpolation algorithm is used to obtain the refined three-dimensional total refractive index field, and the Ray-tracing algorithm is combined to accurately estimate the atmospheric delay of the oblique path of the three-dimensional SAR signal, avoiding the signal projection. to improve the accuracy of the atmospheric delay phase of SAR images, and realize the high-precision correction of InSAR atmospheric delay

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