Comparisons of Speckle Noise Filtering Methods on Interferometric Synthetic Aperture Radar Images

Speckle noise in interferometric synthetic aperture radar (InSAR) phase images seriously degrades the quality of interferogram, disenables interferogram to reflect accurate phase characteristics of the target and increases the difficulty in extracting DEM information of the target area. Therefore, reducing speckle noise by interferogram filtering is a significant step in InSAR processing. First, a noise-included interferometric SAR phase image is simulated based on a terrain model and geometrical parameters of InSAR system. The phase image can be characterized by multilook phase distribution. Then, three interferogram filtering algorithm are explored to remove speckle noise: Goldstain filter, rotating kernel transformation and Lee filter. Proper implementation of three methods is given. Based on experimental results, performances of three different methods are compared. Two aspects need to be comprehensively considered in noise reduction process: the required accuracy in practical application and the processing duration. And also secondtime or multiple combined noise reduction is highly recommended.