SAR Interferogram Phase Filtering Using Wavelet Transform
نویسندگان
چکیده
The application of SAR Interferometry (InSAR) especially in Digital Elevation Modeling as well as deformation monitoring encounters problems due to noise in the interferogram phase. The noise is mainly caused by temporal and baseline decorrelation as well as changes in atmospheric conditions that makes the process of phase reconstruction difficult and reduces the accuracy. The quality of digital elevation models and displacement maps can be improved by filtering the interferometric phase. This paper reviews the methods of for noise reduction of interfermetric phase. It discusses a new algorithm based on wavelet transform which reduces the noise without reducing the spatial resolution or using any window over the interferogram. Comparing this algorithm with the other existing methods shows its strength in reducing the noise and preserving the signal. The effectiveness of the proposed filtering algorithm is tested by applying it to the InSAR results of the Bam earthquake. The results show that the filtering algorithm using wavelet transform is very successful in reducing noise in the interferogram.
منابع مشابه
SAR Interferogram Filtering of Shearlet Domain Based on Interferometric Phase Statistics
This paper presents a new filtering approach for Synthetic Aperture Radar (SAR) interferometric phase noise reduction in the shearlet domain, depending on the coherent statistical characteristics. Shearlets provide a multidirectional and multiscale decomposition that have advantages over wavelet filtering methods when dealing with noisy phase fringes. Phase noise in SAR interferograms is direct...
متن کاملDual Tree Complex Wavelet Transform for Adaptive Interferogram Residual Reduction
A novel scheme for interferogram filtering is presented in this paper. The main concern of the proposed scheme is to lower the residues count mean while preserving the location and jump height of the lines of phase discontinuity. The real interferogram is converted to complex form by using wrapped phase values as an argument of complex exponentially, placing the data on the unit circle on the c...
متن کاملAutomatic Analysis of Photomechanics Interferogram Using Wavelet Transform
An advanced continuous wavelet transform technique has been developed to automatically analyze photomechanics interferograms. This technique utilizes all possible wavelets to match the local interferogram fringes, and it can automatically detect local fringe frequencies and orientations with high accuracies. The advanced wavelet transform technique has the capability to directly determine gradi...
متن کاملFiltering of InSAR interferograms
ABSTRACT: Radar is gaining increasing credibility as a technique for rapid and accurate topographic mapping. Precision and accuracy of elevation and ground displacement assessed from Interferometry SAR (InSAR) depend essentially on phase difference or interferogram quality. The phase noise degrades the visual quality of the interferogram and increases the error in phase unwrapping results. Many...
متن کاملSelective Weighting of Undecimated Wavelet Coefficients for Noise Reduction in SAR Interferograms
This paper describes a technique for noise reduction in synthetic aperture radar interferometry. The noisy interferogram is decomposed using undecimated wavelet transform and the coefficients are weighted. A novel method for computing the weights for each subband, based on an estimate of the relative noise content in them, is presented with a median filter used as the noise estimator. The propo...
متن کامل