Research On DEM Generation Algorithm Of Distributed-based InSAR

The technology of interferometric synthetic aperture radar is a kind of new active microwave three-dimension remote sensing imaging technology which has been developed from the foundation of SAR technology. This technology can fast extract the target's three-dimension information with two or more radars to acquire the interferometric phase data from the same ground target's image pairs. The process with the characteristic of high automation degree povides a new way to fast extract DEM and monitor the change of the topographic.A latest conception, Formulation satellites technology with the breakthrough and the rapid development of the space technology, has become the new trend of the present InSAR technology development with good agility and the trait of meeting the needs of baseline required by InSAR intervening. At the same time, a great progress has been made in the SAR technology, the precision definite orbit technology, the space baseline measurement technology and the InSAR data process technology. so it is possible to extract DEM with high precision from the InSAR data. The main context of the passage is the research on how to get the three-dimension coordinates of the ground points from the phase unwrapped data on the precondition of the high precision accessorial parameters. The major jobs concluded and summarized are listed as follow:①Illustrating the present international and domestic InSAR technology's development trend, expatiating the base principles of the SAR interferometry, then on the basis of which the basic flow of extracting DEM is given from the InSAR data;②Detailedly Illustrating the principles, meanings and solution methods of the existing DEM generation models which is classified into two kinds whose merits and demerits is discussed based on the model's characteristic.③A new DEM generation model is proposed—The Main Imaging Surface model which is the precision solution model of the ground points of which the middle process has no supposing and approximation. Meanwhile it is a solution model based on the geocentric coordinate system, so it needs no correction of earth's curvature. It combines the elevation transformation from phase and the geographic coordinates coding together and directly get the ground points'three-dimension coordinates.The model adapts to DEM generation of distributed-based.④Validating the legitimacy, the complex topography process capability and the solution accuracy of the Main Imaging Surface model by the analogue data, the simulation data and the real data. By analyzing the results analysis, no iteration, no ground spot initial values are required for this model. The solution is fast with assured accuracy.