Application Research Of InSAR Detection Technology For Surface Deformation In The Xingyun Lake Area

Synthetic aperture radar interferometry(InSAR)technique has been 40 years of the birth of time,and with its constant development,it has been playing an increasingly important role in the surface monitoring.InSAR technology is mainly used for acquiring surface elevation information at first.After nearly 20 years of development,InSAR technology turn into another stage of development,namely the differential synthetic aperture radar interferometry(D-InSAR)technology.D-InSAR is a all-time,all-weather,active microwave remote sensing of the earth's surface deformation monitoring technology.It can be used to monitor the large area surface deformation,especially in the sudden surface deformation caused by underground mining and landslide or earthquakes,it's monitoring effect is well,and it can make up for some of the flaw of traditional surface deformation monitoring methods,such as:monitoring range is small,dependent much on manual operation,no way to deploy monitoring points in harsh natural conditions of the region,etc.,therefore,D-InSAR technique has been developed quickly in the application of surface deformation monitoring.But at the same time,it has gradually revealed some disadvantages in the long slow ground deformation monitoring.The D-InSAR processing faces time and space loss of coherence and the atmospheric disturbances if data of long time interval,in this case,the time series InSAR arises at the historic moment.The SBAS-InSAR(Small Baseline Set InSAR)is based on a series of time series data,and all data are grouped according to the space and time baseline threshold.Then proceed differential interference in each small baseline sets.At last obtaining the total deformation for period of time by least square method or singular value decomposition method.SBAS InSAR technology can effectively solve the D-InSAR technology facing the space and time loss of coherence and atmospheric interference problem,in the earth's surface slowly deformation monitoring applications widely.Fault zone is widely distributed in,and yunnan province is one of the provinces and cities of the earthquake disasters in our country.Xingyun lake is a rift lake developed by xiaojiang fault zone located in yuxi jiangchuan county.Xiaojiang fault zone didn't caused a big earthquake in recent years,but it has been slow movement.It is of great significance to the security of the xingyunhu region to use SBAS-InSAR technology monitoring the slow surface deformation of xingyun lake around areas.In this paper,the main work and results are as follows:1)Through the different methods of filtering and unwrapping experiment,comparing the results,this paper argues that the the most appropriate filtering method is Goldstein in research area,and the most appropriate unwrapping method is minimum Cost Flow.2)SBAS-InSAR technology demands the higher surface coverage conditions in it's application,with the coherence value of 0.35 at the first experiment,it only finds housing,and adjust coherence value is 0.1,the result still didn't get the deformation information from vegetation region,by contrast,D-InSAR technique demands low surface coverage conditions.3)SBAS-InSAR technology can effectively overcome the error from DEM.The radar data in water area is black,with no valid values.Experiment uses 90-meter resolution DEM,and the DEM data in water body part has some error,but through a series of processing of SBAS-InSAR,the results did not introduce the the error of water,deformation results still present black in water body parts,without deformation information,but D-InSAR will DEM introduce error of water in the final deformation results.4)Through monitoring the ground surface deformation of xingyun lake surrounding areas in more than one year,the experiment finds that the region's most significant surface deformation does not occur,and jiangchuan county andthe north river town of hezui village,liuzui village,maliao village at near xingyun lake have the surface subsidence,subsidence quantity is concentrated in the 16 to 7 mm range,deformation and deformation rate of the figure shows that the total deformation and deformation rate have good consistency.Test results show that the SBAS-InSAR technology demands higher surface coverage condition,but it's monitoring effect is well for the slow surface deformation.It can be widely applied in the urban concentration of long-term slow surface deformation monitoring work,plus it's data update speed and the corresponding processing software tend to be more practical,so SBAS-InSAR technology application in monitoring the earth's surface deformation will be more and more mature.