Research On Registration Method Of Mountainous SAR Images

Nowadays,InSAR technology is an important means of large-scale and high-precision geological hazard monitoring.The SAR image registration is the key step of InSAR technology,the accuracy of which directly affects the reliability of the final results.However,there are obvious geometric distortion about the SAR images obtained in mountainous terrain areas because of the particularity of SAR imaging system,which makes the traditional SAR image registration methods difficult to meet the registration requirements of mountainous SAR images.Aiming at the difficult problem of SAR image registration in mountainous areas,a SAR images registration method for mountainous area is proposed.and experimental verification was designed bythe registration accuracy and land subsidence monitoring respectively.The contents of this paper are as follows:1.The point set matching algorithm of vector field consensus is deeply analyzed.Firstly,the SIFT algorithm is used to roughly match the two images,and then the matching relationship is transformed into the sample set of the image vector field with outliers.Finally,the outliers in the sample set of the image vector field are eliminated by the VFC algorithm,and the accurate image vector field is estimated,so that the accurate point correspondence relationship is established.Compared with SIFT matching algorithm,theexperimental results show that the method can improve the accuracy of image matching.2.A SAR image registration method suitable for mountainous areas is proposed.First,The proposed method generated a simulated SAR image,Then a point matching algorithm of vector field consensus was used to the matching of the simulated SAR image and the real SAR image,thus getting the feature points of real SAR images indirectly.Finally,the accurate registration of SAR images was achieved by polynomial transform for mountainous area.Experimental verification was designed by using the data of mountainous SAR images of the same sensor and different sensors respectively.The experimental results showed that the registration accuracy of this method had improvedgreatly compared with the traditional SAR images registration method,and could effectively solve the registration problem of SAR images for mountainous area.3.The principle of D-InSAR technology is analyzed in this paper.The proposed image registration method is applied to the experiment of land subsidence monitoring using D-InSAR technology.The experiment uses TerraSAR data in Taiyuan area and SARscape software.The results of land subsidence in Taiyuan area was obtained by experiment,and the results were compared with those obtained by SARscape software.The feasibility and validity of the image registration algorithm in land subsidence monitoring in mountainous areas were verified.