Study On ENVISAT ScanSAR Interferometry For The Data Processing

Scanning spaceborne synthetic aperture radar interferometry is athree-dimensional measurement technique that SAR satellites monitor the earth’ssurface and process corresponding radar data to get deformation information by usingscanning mode, also known as ScanSAR interferometry. Compared to conventionalInSAR interferometry, despite its lower resolution, It has the advantages of largecoverage, large range and short time interval to monitor the large-scale surfacedeformation. With melioration and enhance of facility and orbit technique of SARsatellite, many SAR satellites, with wide scanning mode, have been launched or willbe eradiated so that they can provide more abundant data for WSInSAR. It also hasprovided opportunities for a wide range of deformation monitoring of earthquakes,glaciers, flood, permafrost and other issues. ScanSAR interferometry has become apotential measurement technique of geological disasters, and will also become a hottopic in InSAR technology.Although wide swath mode is one of modes of spaceborne SAR satellites，compared to conventional InSAR, wide swath SAR interferometry is very different inimaging mode, imaging principle, data collection methods, process of interferometry,such as strip mosaicing, sub-band processing, coregistering and so on. In order thatScanSAR interferometric techniques can be used to monitor a wide deformation field,this paper systematically studies the theory and the application of scanning syntheticaperture radar interferometry, and puts forward the sub-bands processing method andthe improved method of coregistering and weighted strip mosaicing, including themain following contents:(1) The paper reviews and summarizes the domestic and foreign research statusof ScanSAR interferometry, and compared to conventional InSAR, the paperdiscusses its advantages and analyzes the purpose and significance of the paper.(2) The paper analyses and discusses the basic theory of the scanning spacebornesynthetic aperture radar, including its imaging principle, operating mode, imagingparameters, three common imaging algorithms of ScanSAR, among which the paper details the Improved SPECAN algorithm.(3) The paper analyses interference principle of ScanSAR interferometry, as wellas the processing method and improvement of the key points. And it includes theprocess of the key points of geoid undulation, atmosphere effects, strip mosaicing andso on，and compared laminated strip mosaicing with the method of coregistering andweighted strip mosaicing, proposes a new improved method. On this basis, the paperpresents the technology roadmap.(4) The paper applys ScanSAR interferometric techniques on the study area ofQinghai-Tibet Plateau for experiment and analysis, and obtains the final improvedresults. The paper also makes comparative analyses of the method of coregisteringand weighted strip mosaicing, and illustrates the effectiveness and reliability of thismethod, and also illustrates the feasibility and reliability of ScanSAR interferometryfor large-scale deformation monitoring.