The Study Of Land Subsidence Monitoring Technology Based On SBAS-InSAR With High Resolution

Land subsidence is irreparable damage for environmental and resources under the natural and the man-made factors. Natural factors include earthquakes, crustal movements, volcanic eruptions, climate change and soil consolidation, etc.; Human factors refer to the exploitation of natural underground fluid, solid minerals mining underground and surface loading and other human engineering activities.Conventional land subsidence monitoring methods not only need a heavy workload, lots of funds, long measurement period, but also have random errors which led to reducing monitoring accuracy. D-In SAR technology with the advantages of large area, high resolution, all-weather and all-time, is a promising means for ground deformation monitoring and disaster prediction, providing a new way of earth observation from space, however the decorrelation factors due to time and space, error, atmospheric phase and atmospheric delay tends to reduce the accuracy of the deformed information, which restrict the D-In SAR applications. SBAS-In SAR was formally proposed in 2002 by Berardino and Lanari et al. it can solve problems related to geometric decorrelation, and it fit for non-urban areas of surface deformation field of time evolutionary analysis.The differential interferometry was introduced in this article, the basic principles of In SAR height measurement and D-In SAR deformation measurement were elaborated, then analyzed the error sources and limitations, and on this basis introduced the principle and process of SBAS-In SAR, further establishing space differential phase model in SBAS-In SAR, discussing the key technologies of data processing. SBAS technology used in surface deformation monitoring has its own unique advantages, which can effectively overcome the loss of coherence phenomena in time and space, increase time sampling rate, compared to other timing analysis methods, there are fewer requirements on the numbers of images.In this study, collected 12 high reselution Terra SAR-X data in Jakarta from June 2010 to March 2011, and used D-In SAR and SBAS-In SAR in study area. Obtaining differential interference fringe and deformation value in time series, interpolation and deformation contours are applied to get continuous deformation senses, besides constructed the three-dimensional model of the deformation field, some subsidence centers are analyzed by deformation time series. It can be concluded that based on high resolution Terra SAR-X data, the time and space subsidence information in Jakarta can be given out with SBAS-In SAR, and the work of subsidence mitigation can be supported by them. It has been found that the residual phase coming from the height error of high buildings would seriously disturb the ground deformation analysis, special methods should be developed to resolve the problem in the future.