Space The Insar Extract Dem

It is one of the best techniques to derive DEM from INSAR(Interferometric Synthetic Aperture Radar). Particularly the space-borne INSAR systems are widely noted by the international organizations of surveying and mapping for the quality of the images is stable and the DEM can be derived without the limitation of the state borders. The basic theories and methods of INSAR were deeply studied in this paper. The breakthroughs were achieved in some methods, which included the registration of the single look complex images, the filtering of the interferogram, and the estimation of the baseline, etc. Finally, a more available INSAR-DEM software system was realized with all the processing functions. The main contexts studied in this paper are list as follows:1. The principles of SAR imaging processing were introduced. The theories of the synthetic aperture and the pulse compress were illustrated with the viewpoint of linear frequency modulation signal and its matching filter.2. The model of the parallax between the master image and the slave one induced by the ground elevation was firstly educed aiming at the characters of INSAR.And so, it was presented that the parallax induced by the ground elevation is little according to the analysis. Some strategies of image matching such as enlarging the matching windows and the points' space. So, the accurate and reliable image matching was realized for INSAR complex images automatically and rapidly by rough registration using orbit parameters.3. A new vector filtering method was designed and realized It can be easy and simple for the phase unwrapping using this filtering method. What's more, it was presented that the noise filtering is a key technology in the INSAR processing according to the experiment's results.4.Some methods of phase unwrapping are studied, and the Vector-filtered inteferograms are successfully used in unwrapping with the direct-recursive method and the line extraction one.5. A new method to estimate the baseline parameters using the phase of flat earth was presented. The method can improve the precision of base estimation. What's more, the method was changed so as to we can use two or more elevation points to estimate the baseline and enlarge the applying scopes.6.A whole INSAR-DEM software system with self-copyright was realized.The wo?of this paper makes some progresses for INSAR processing. The research results are expected to be converted into the practical technology for deriving regional DEM from INSAR remote sensing data.