InSAR DEM Accuracy Analysis And Quantitative Evaluation

Interferometric Synthetic Aperture Radar(In SAR)not only has the advantages of all day,all-weather,long-range and high-resolution imaging,but also makes up the shortage of Synthetic Aperture Radar(SAR)in 3D stereoscopic imaging.Thanks to its capability of obtaining high-precision Digital Elevation Model(DEM),In SAR has found wide applications ranging from terrain mapping,surface monitoring,inversion of forest elements to military scouting.However,due to the influence of data processing errors and system errors,the reconstruction accuracy of In SAR DEM is far from being satisfactory.This paper provides a systematical study of the In SAR DEM reconstruction technology.The reconstruction process of In SAR DEM,along with the reconstruction error sources and the reconstruction quality evaluation methods,are discussed and analyzed in detail.The main content of this thesis can be concluded as three sections:1.An introduction to principle of In SAR height measurement is given,which is used as a basis for the detialed reconstruction process of In SAR DEM.First,the geometry model of In SAR is introduced,and its feasibility is analyzed.Then,according to the reconstruction process of In SAR DEM,that is,SAR data preprocessing,image registration,flat phase removal,interferometric phase filtering,interferential phase unwrapping and DEM generation,the steps of DEM reconstruction are analyzed in detail,and the effectiveness of the algorithm is verified by simulation data and real measured data.Finally,the reconstruction of In SAR DEM is realized based on the simulation data of the master and slave SAR image.It provides a theoretical basis for the follow-up study of In SAR DEM reconstruction error analysis and reconstruction quality evaluation methods.2.Based on the In SAR DEM reconstruction theory,the error sources affecting the reconstruction accuracy of In SAR DEM are studied.Firstly,the In SAR DEM reconstruction error is analyzed and classified according to the parameters that affect the target elevation reconstruction.Secondly,the influence of different parameters on the reconstruction error of In SAR DEM is analyzed.Further,the relationship between the main parameters and the In SAR DEM reconstruction error is analyzed,and its validity is verified through simulation data.Finally,using the least squares adjustment method adopted by Tan DEM-X system,the system error of In SAR is adjusted and the influence of systematic error on DEM reconstruction is reduced.3.From the perspective of controlling the reconstruction errors of In SAR DEM,a systematic method for measuring the quality of In SAR products is proposed.Following the reconstructing procedures of In SAR DEM,the evaluation methods for SAR imaging quality were studied at first,such as the peak side lobe ratio,integral side lobe ratio,image resolution,azimuth ambiguity,mapping bandwidth and etc.Then,the evaluation criterions for In SAR imaging performance were measured,such as image matching accuracy,interferometric phase loss,elevation reconstruction accuracy,geometric distortion amount and etc.Based on these measurements,the In SAR quality elevation system is developed.Finally,the effectiveness of the proposed performance evaluation methods is verified by the evaluation results assessed by simulation software.