Acquiring3D Coseismic Deformation Field Of Bam Earthquake By Using D-InSAR And MAI Techniques Weighted

InSAR is the product of the traditional SAR technology combined withinterference technology, while D-InSAR technology is an extension of the InSARtechnology. It is considered a new potential developed satellite earth observationtechnologies for it’s centimeter or even millimeter accuracy in terms of surfacedeformation monitoring. D-InSAR technology has advantages of wide coverage,high-resolution and high sensitivity perpendicular to the ground deformation relativeto other traditional deformation measurement technique such as GPS measurements,leveling, etc. But the deformation of the seismic zones got by traditional D-InSARtechnology is the deformation in direction of radar line-of-sight, which is theprojection of vertical, east-west, north-south three directions deformation in thedirection of the radar line of sight. When an earthquake occurs, not only physicalvariables in the vertical direction, but also there will be a large deformation in thehorizontal direction. D-InSAR technology has high precision in the vertical directionmonitoring while but not sensitive to the north-south direction deformation. Inaddition, only two observations by ascending-pass data and descending-pass data thethree-dimensional deformation can not be solvered and must be used other techniquesand methods.This paper presents a method for the specialized monitoring in the track direction(also known as the azimuth, similar north-south) deformation method-MultipleAperture InSAR. In EnviSAT ASAR data, for example, the technology has theadvantages of high accuracy in monitoring the north-south direction, which isprecisely to make up for the lack of D-InSAR technology. In this paper, threedeformations combined the vertical deformation acquired by D-InSAR technologyand azimuth deformation acquired by Multiple Aperture InSAR technology and weighted by three different method-Equal Weight method, Robust Least Squaresmethod and deformation images standard deviations method. The three-dimensionaldeformation field of Bam in2003is created.Finally, in order to evaluate the accuracy of three-dimensional deformation field,a three-dimensional coseismic deformation model in seismology is introduced-theOkada elastic half-space Mode for lack of GPS data or level data. In this paper, thismodel is regarded as the true value to evaluate accuracy of three-dimensionaldeformation field solvered by SAR data. The weight ratio between the D-InSARtechnology and MAI technology is3.72~4:1when used Robust Least Squaresmethod and that is0.92~1000:1when used deformation images standard deviationsmethod. The results showed that the the accuracy of weighted east-west direction datais improved up from decimeter to centimeter. The centimeter-level accuracy ofvertical direction is remained while decimeter-level accuracy of east-west direction isremained, too. The results also show that the result of north-south direction isunreliable while east-west direction and the vertical direction is reliable.