PS-InSAR phase unwrapping method based on time domain difference and system and application thereof

Abstract

The invention discloses a PS-InSAR phase unwrapping method based on time domain difference and a system and application thereof, and the method comprises the steps: obtaining an arc segment differential interferometric phase of a differential interferogram of a synthetic aperture radar image through the setting of a permanent scatterer point; dividing the winding number of the phase into phase winding caused by terrain residual difference and winding caused by deformation difference, solving the phase winding and the winding respectively so as to unwind the segmental arc phase, then obtaining estimated values of deformation rate difference and terrain residual difference through a least square method, and calculating the phase winding number of the segmental arc phase through a net adjustment method. And direct calculation of the deformation rate, the terrain residual error and the deformation time sequence of the permanent scatterer point is realized. According to the method, the problems of low unwrapping efficiency, serious resolving time consumption, insufficient nonlinear deformation recovery and low precision when PS-InSAR is used for large-range deformation monitoring under mass data can be effectively solved, and high-precision rapid resolving of parameters and direct recovery of a deformation sequence are realized.

Description

technical field [0001] The invention relates to a synthetic aperture radar interferometry (InSAR, Synthetic Aperture Radar Interferometry) technology in the field of geodesy based on remote sensing images, in particular to a PS-InSAR fast unwrapping and deformation sequence recovery method based on time domain difference. Background technique [0002] Synthetic aperture interferometric radar (InSAR-Interferometric Synthetic Aperture radar) has the advantages of high precision, large range, all-weather, all-weather, and has been greatly applied and developed in surface deformation monitoring. Based on its permanent scatterer synthetic aperture radar interferometry (PS-InSAR), it has been successfully applied to various deformation monitoring, including landslides, urban subsidence, infrastructure subsidence, mining subsidence, etc. Millimeter-level deformation monitoring results. Thanks to the launch of various SAR satellites in recent years, especially TerraSAR-X, COSMO-Sky...

AI Technical Summary

Problems solved by technology

However, due to the lack of more accurate noise prior information, the solution accuracy of this method cannot be guaranteed, and unwrapping errors are prone to occur; the solution space search method and the periodogram method convert the Euler formula or the spatial phase into the frequency domain, It avoids the influence of the whole circle ambiguity on the calculation of arc segment parameters, but this type of method is easily affected by the parameter setting of the boundary of the solution space, and the line efficiency is relatively low

In the subsequent deformation sequence calculation process, we still have to face the problem of residual phase unwrapping; the three-dimensional deformation unwrapping method represented by Hooper introduces time domain information to improve the accuracy of unwrapping, but still faces the problem of unwrapping The efficiency is low, and it is only suitable for the problem of small-scale deformation calculation; the method represented by TCPInSAR can realize phase unwrapping and parameter calculation by empirically eliminating the arc segments with whole-cycle jumps, but this kind of method has no The elimination of arcs often depends on the empirical threshold, and it is easy to destroy the stability of the PS network, and even create "islands", which makes the solution fail

[0004] According to the above analysis of the existing PS-InSAR phase unwrapping methods, it can be seen that the above-mentioned types of methods all have the problems of high computational complexity and the problem that the computational accuracy is easily affected by parameter settings. At the same time, the above-mentioned mainstream methods still have problems Solving common problems that are time-consuming and require high hardware equipment severely reduces the flexibility and convenience of the PS-InSR algorithm

Therefore, how to achieve high-precision, high-efficiency, and high-stability PS-InSAR phase unwrapping is still one of the main problems hindering the update and large-scale application of PS-InSAR algorithms.

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