A New Filtering Technique for Interferometric Phase Images

-This paper proposes a new technique for noise reduction applied to interferometric phase images. It involves a non-linear filtering system that not only eliminates noise in interferometric phase images, but also re-introduces detail information to the phase image. To implement the filtering system, a modified pivoting median filter with adaptive window size dependent on coherence is firstly used to smooth out the noise present in the image to a certain extent. It is then cascaded by a fringe smoother with different directional windows. The detail component of the interferogram is obtained by subtracting the smoothed signal from the original signal. It is then smoothed by a non-linear smoother with a large window and last added back to the smoothed signal to generate the final output. The experimental result on real data shows that the performance of the proposed technique outperforms some other phase filtering techniques, especially when comparing the DEM to the ground truth data. Keywords—SAR interferometry, Interferogram, phase noise filtering