A Precise Estimation Method of SAR Interferometric Baseline Based on Flat-Earth Phase

Abstract

The invention discloses an SAR interference baseline precise estimating method based on a flat-earth phase. The method comprises the steps that according to the geometrical relationship of an SAR interference baseline and the flat-earth phase, a rigorous SAR interference baseline estimating adjustment model is built, the geometric structure of baseline estimation is transferred to a regular reference ellipsoid face from the fluctuant and changing earth surface, and an iterative unknown parameter solution algorithm combining ridge estimation and truncated singular value decomposition is provided. According to the SAR interference baseline precise estimating method, the survey adjustment theory and an InSAR theory are organically combined, and the method comprises the following steps of (1) data preprocessing, (2) systemic signal removal, (3) model building and (4) model resolving. The SAR interference baseline precise estimating method is visual in principle, facilitates programming realization and application, is stable and reliable and can be used for improving the precision of measurement of the InSAR technology.

Description

technical field [0001] The present invention relates to Synthetic Aperture Radar Interferometry (InSAR, Synthetic Aperture Radar Interferometry) technology, in particular to a method for accurately estimating SAR interferometric baseline based on flat earth phase. Background technique [0002] After more than 20 years of development, the theory of Synthetic Aperture Radar Interferometry (InSAR) technology has been gradually improved, and it has been widely used in terrain mapping and surface deformation monitoring. In recent years, its application fields have gradually expanded from large-scale macro monitoring such as earthquakes, volcanoes, and urban surface subsidence to fine monitoring of infrastructure such as bridges, dams, and buildings, as well as high-precision 3D reconstruction of cities. The prospect is very broad. [0003] However, InSAR measurement accuracy is affected by various errors, such as atmospheric delay error, DEM error, random phase error, and baselin...

AI Technical Summary

Problems solved by technology

But in many cases, we can't get the ground control points in the study area

According to the relationship that the control point is the intersection of the slant-range ellipsoid, the Doppler cone and the earth ellipsoid, some researchers use an iterative method to calculate the elevation of the ground control point, and then use the above-mentioned least squares baseline estimation method to solve the baseline. However, The control point elevation obtained by iterative calculation has limited accuracy

[0008] According to the above analysis of the existing InSAR interferometric baseline estimation methods, it can be seen that these methods have inherent defects, and cannot obtain high-precision baseline estimation results, resulting in the inability of InSAR interferometry technology to achieve its due theoretical accuracy, thus affecting promotion and application of the technology

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