The intensity of a Sentinel-1 Terrain Observation with Progressive Scans synthetic aperture radar image is disturbed by additive thermal noise, particularly in the cross-polarization channel. Although the European Space Agency provides calibrated noise vectors for noise power subtraction, residual noise contributions are significant when considering the relatively narrow backscattering distribution of the cross-polarization channel. In this paper, we investigate the characteristics of noise and propose an efficient method for noise reduction based on a three-step correction process comprised of azimuth descalloping, noise scaling and interswath power balancing, and local residual noise power compensation. The core idea is to find the optimal correction coefficients resulting in the most noise-uncorrelated gentle backscatter profile over a homogeneous region and to combine them with the scalloping gain for a reconstruction of the complete 2-D noise field. Denoising is accomplished by subtracting the reconstructed noise field from the original image. The performance improvement in some applications by adopting the denoising procedure shows the effectiveness of the proposed method.
|Number of pages||11|
|Journal||IEEE Transactions on Geoscience and Remote Sensing|
|Publication status||Published - 2018 Mar|
Bibliographical noteFunding Information:
Manuscript received September 27, 2016; revised April 4, 2017 and July 3, 2017; accepted October 13, 2017. Date of publication December 4, 2017; date of current version February 27, 2018. This work was supported by the Research Council of Norway and the Russian Foundation for Basic Research under NORRUSS Project 243608, SONARC.
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All Science Journal Classification (ASJC) codes
- Electrical and Electronic Engineering
- Earth and Planetary Sciences(all)