Study Of InSAR Data Processing Methods And Application

Interferometric Synthetic Aperture Radar (InSAR) is a main profile of satellite SAR application. InSAR images can be used to produce DEM. It can monitor movements on earth surface such as earthquake, volcano, atmosphere meteorology, ice sheet movement, subsidence, landslide, and so on, at centimeter or even more minute levels with D-InSAR images.With the development of InSAR, the accuracy of result is more and more high. Thus affection of accuracy will be researched more further. Onboard repeat pass InSAR formed interferogram with SAR images, extracting useful signals. Atmospheric effects is the main source of error. For ionosphere, because it does not have much changes in vertical direction, it will not affect the interferogram much. Under the existing research and information, troposphere is the main factor for atmospheric delay.In response to these issues above, we calculated the tropospheric delay above CGPS network stations, done some research on InSAR atmospheric delay interpolation model in rainy mountainous area and on the number of tropospheric estimated parameters. Firstly, three pass D-InSAR atmospheric delay model is derived on the basis of double-difference model of atmospheric delay. Then, the tropospheric delay above New Zealand GEONET GPS network stations is calculated with Bernese GPS software. According to single or double difference model, we got the differential tropospheric corrections. The interpolation maps is produced with IDW model and Kriging model and their advantages are analysed. We have done some research on the number of tropospheric estimated parameters with part of GEONTE. By the research, it is found that the differential tropospheric delay is at centimeter level which is very important for us to get a sub-centimeter result in D-InSAR. IDW and Kriging model are very suit for rainy mountainous area. Five minutes interval is reasonable for tropospheric correction with GPS data.For it's rainy and mountainous, many geological disasters happened more easily in Chongqing which is located in southwest of China. It is particularly important to do some research on this area on InSAR technology. With the conclusions of GEONET study in New Zealand, the tropospheric delay is studied as well as affection of tropospheric delay on InSAR. The study show that the tropospheric delay is beyond 2 meters to microwave signals which is very important to surveying, meteorology, telecommunications and so on. And the tropospheric delay is at centimeter level on InSAR which is very important to get a sub-centimeter result for monitor of surface deformation with D-InSAR.Because of the complexity of the process and strict conditions, the common researchers can hardly do any research unless you buy expensive commercial software. We generate DEM and study the surface deformation with radar images through the open-source software Doris that is developed by Delft University of Netherlands. The processing of radar data with Doris is described. With the Doris, the DEM before earthquake and deformation field after earthquake in Bam area of Iran are generated as well as comparison of result with several research centres in the world. The interference can be available with Doris software which is not inferior to commercial software.