The Research On Permanent Scatter Target Extract Method Of PSInSAR Technique

Compared with traditional leveling and GPS, Interferometric Synthetic Aperture Radar, In SAR technique has more salient advantage of speediness, large area observation, full weather, full time and lower cost in deriving three-dimensional and deformation information of earth surface, and has become one of the most potential earth observation. With the restrictions of decorrelation and atmosphere delay influnce, however, traditional DIn SAR technique do not apply to slow deformation measurement of surface for a long time.on the base of this, the permanent scatters In SAR technique(PSIn SAR)has a great development,it solve the problems facing the application of DIn SAR techniques, such as low coherence, signal delay caused by atmospheric. And precision of PSInSAR technique detect deformation rate is millimeter level and has been used in city ground deformation monitoring, dam deformation monitoring and coast monitoring.Thereby, on the foundation of reading the relevant literature,this paper comprehensively introduces the basic principles and data processing of satellite In SAR, DIn SAR, and systematically study and summarizes the theory of the Persistant scatters In SAR technique,then, this paper investigates the identification and selection of permanent scatters of PSIn SAR comprehensively and systematically. It takes three set of experiments after comprehending the basic ideas of several PS detection algorithms. Firstly, This thesis emphatically analyses two conventional PS detection algorithms which are correlation-coefficient and amplitude dispersion index. It analyses the advantages and disadvantages of the two kinds of conventional methods through the results. Then, focusing on the advantages and disadvantages of the two conventional algorithms, it adopts the dual threshold method which combines correlation-coefficient and amplitude dispersion index to complete the PS targets detection experiment. Through the compassion of the dual threshold method and two conventional methods, it verifies the reliability of the dual threshold method and points out its existing problems.Finally, considering both PS’s stableness and the strong scattering characteristic of radar backscattering, it uses the triple thresholds method based on correlation-coefficient, amplitude and amplitude dispersion index to identify and select permanent scatters. Through the analysis of the experimental results of the triple thresholds method and the dual threshold method,verify the validity and reliability of the three threshold method.