Landslide Deformation Monitoring And Analysis With GB-SAR

Landslide is one of the fairly common typical geological disasters surrounding the SiChuan basin. On the one hand, it is affected by the internal tectonic movement of the earth itself, etc. On the other hand, it is also affected by irrigation facilities and underground engineering and other human activities. It causes enormous economic lossesand serious caualties. Therefore, it is necessary to make timely and accurate monitoring for emergency management and to determine the appropriate precautions. It is imminent to develop a new scientific and effective way for landslide monitoring and early warning technology. There are many limitations and shortcomings in the existing ground monitoring methods and space remote sensing technology, such as spatial resolution, measurement accuracy, climate conditions, constraints, the validity of timeliness and so on. In recent years, Ground Based Synthetic Aperture Interferometry Radar (GB-SAR) has been made a substantial progress in the field and fully showed its great potential applications and important practical significance and economic value.However, in practice, GB-SAR can be influenced by atmosphere in the course ofmonitoring due to its short-wave. Different scholars propose different techniques that existed limitations due to the complexity of the atmosphere, an effective unified model has not been established.To solve the problem, this research proposes a multi-model atmospheric correction algorithm based on different scholars, and then, we apply the multi-model in landslide monitoring and analysis. Furthermore, GB-SAR with slant-range projection, there is a big difference between the images with the optical image especially in a complex mountainous terrain, so that the image is very difficult to interpret. Based on this, this research has been improved the projection correction based on the viewshed analysis. The details are as follows:(1) We have developed a three-dimensional moving platform based on different scholars on the development of the corner reflector. The platform has the characteristics with high accuracy, easy operation, stability, small size and so on. It can be simulated a three-dimensional moving and verify the precision of the instrument.(2) This research proposes a multi-model atmospheric correction algorithm. The model is formed as an automatic integration process from the stable point selected, model selected, accuracy assessment aspects. This algorithm is selected valid point based on SNR and phase stability. It compares different models according to the number of stable point in the time domain, and selects the appropriate model. It reduces errors caused by human intervention. It was applied in landslide monitoring and atmospheric analysis and achieved good results.(3) Projection correction based on viewshed analysis. In order to eliminate the error in projection correction effectively, the obtained data were viewshed analysis before projection correction. It removes invisible region in radar perspective and improve search efficiency and reliability. It shows that the algorithm has practical feasibility through simulation experiments.(4) Landslide monitoring and analysis with GB-SAR in Yaan Qiaoqi dam. The atmospheric was removed effectively by the multi-model correction in this monitoring, the research analysis space-time evolution characteristics of the landslide combined with the data and the actual survey, it shows that the landslide has creep properties. There are two relative large regional deformation in the monitoring area, it is worth special attention.Theoretical and experimental studies have shown that multi-model correction algorithm has the advantages of automatic integration and reduces the atmospheric correction error by human operating, which shows a good applicability in landslide monitoring. The projection correction algorithm based on viewshed shows it can effectively improve the reliability of projection correction and its practical feasibility through simulation.