The Research Of Analysis And Denoising In Interferometric Synthetic Aperture Radar

Based on the Synthetic Aperture Radar technology,the Interferometric Synthetic Aperture Radar calculates the velocity information and the elevation information through the interferometric phase.In this process,the appearance of noise is inevitable.This paper eliminate the noise by using median filter,average filter and wavelet filter methods to get more accuracy information in Distance-Doppler algorithm.Firstly,this paper use the Distance-Doppler algorithm to require the target image.On this basis,a single-point target and a three-points target simulation experiment are realized,which is the base for the analysis of velocity and elevation.The median filter,average filter and wavelet filter methods are introduced for the source of noise in synthetic aperture radar(SAR)measurements.In the second part,the computation formulae between interferometric phase and the velocity of moving targets are deduced.Because the traditional single baseline is limited to get non-fuzzy velocity range,the multiple baselines with remainder theorem can make the non-fuzzy velocity range to a reasonable range.In the different SNR environment,the average denoising method is used to analyze of noise impact on data estimation.Whether the velocity in non-fuzzy velocity range,the average denoising method eliminate the interfere of the noise.Finally,In this paper,a new method of elevation inversion based on polar coordinate system is proposed on the basis of the classical elevation measurement.In this method,a polar coordinate system based on radar platform is established,and the polar coordinate equations between radar interference phase and target scattering point are derived.In order to obtain the altitude information of the scattering point,the angle of the target scattering point is obtained.After analyzing and contrasting the elevation information obtained by the classical Cartesian coordinates algorithm,it is found that the computation speed and accuracy of polar coordinates elevation inversion are better than the classical Cartesian coordinate system.In the different SNR environment,the new method is used to estimate the elevation,using median filter,average filtering and wavelet analysis to denoising,and comparing those denoising effect from subjective image observation and objective data analysis,finding that the average filtering method has the best performance.Above all,this paper uses median filter and remainder theorem to get the true velocity;meanwhile using median filter,average filter and wavelet filter to get the elevation information based on the analysis of Interferometric Synthetic Aperture Radar and polar coordinate system in noise environment.