Applied Research Of D-INSAR Technology In The Landslide Information Extraction

As a common natural geological disaster with strong destructive effect, whichcauses mudslides and mountain collapse, the landslide often causes huge losses inpeople’s life and property security and nation-building. So the monitoring of thelandslides is the effective means of the dangerousness of reducing the disaster. With thedevelopment of interferometric synthetic aperture radar (InSAR) technology, thedifferential synthetic aperture radar interferometry is an application of the InSAR,which has a lot of features, such as, wide coverage, high spatial resolution, all time, allweather, large region, high sensitivity and so on, and it can detect the slight deformationof the surface with centimeter-level ability to detect, even a smaller dimensionalaccuracy. It can obtain the ground elevation information with high-precision andhigh-resolution. What’s more, by the comparison of two interferograms before and afterthe landslide disaster, it achieves the precise measurement of the landslide surfacedeformation before and after the landslide disaster. So the paper uses the D-INSARtechnology to do research on the deformation information extraction of the landslide.This paper systematically expounds the development course, application status ofthe synthetic radar interferometry, the SAR imaging principle and the basic principle ofInSAR. On the basis of it, InSAR technology process in detail is lucubrated, and the keyprocessing steps are discussed and analyzed. At the same time, using programmingsoftwares programming to realize the function of the algorithms of key steps are added.The main contents include the following sections: two main and auxiliary images formthe interferometry, flat earth phase removal, phase noise filtering, baseline estimation,phase unwrapping, height conversion and deformation extraction. Finally using thealgorithms the paper mentioned, the paper mainly carried out the main steps of INSARprocessing with the data of RADARSAT-2, processing experimental data and verifyingthe main steps’ implementation. Among them, the method of flat-earth phase removalbased on the orbital parameters, by fitting satellite orbital equations, avoids multipleiterations of the complex operation, which improves the operation efficiency. Andseveral filtering methods are compared and discussed, and the residual number, signal-to-noise ratio and the integrity of stripe edge are analyzed. In conclusion, theadaptive median filter has a better filtering effect. The path following method is used forprocessing the phase unwrapping,.which advantage lies in the short operation time.Finally with the D-INSAR the SAR images with landslide information are carried onextracting the landslide surface deformation information. The result shows that theprecision of the D-INSAR technique can be the level of cm in extracting thedeformation of the small landslide.