Filtering of multichannel SAR images
- 1 November 2001
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Geoscience and Remote Sensing
- Vol. 39 (11), 2373-2379
- https://doi.org/10.1109/36.964973
Abstract
An explicit form of the linear multichannel synthetic aperture radar (SAR) intensity filter, which preserves radiometry while optimally reducing speckle is derived, together with a compact expression for the theoretical gain in equivalent numbers of looks (ENLs). The filter can be applied to mixed data types, which is demonstrated using a combination of ERS and JERS satellite data, and confirms the filter performance predicted by the theory. Tests indicate that a simplified form of the filter, which neglects correlation between images, gives an ENL only slightly less than optimal, while being much easier to implement. Exact analysis of the effect of estimating filter weights shows that the linear increase in ENL with the number of images predicted for the ideal filter does not occur. In practice, the ENL is affected by the window size used to estimate the weights and saturates as the number of images increases. An efficient recursive form of the filter is described, which is most naturally applied to multitemporal data for the practically important case where the current image is uncorrelated with previous images in a data sequence.Keywords
This publication has 6 references indexed in Scilit:
- Multitemporal ERS SAR analysis applied to forest mappingIEEE Transactions on Geoscience and Remote Sensing, 2000
- Quantitative comparison of the performance of SAR segmentation algorithmsIEEE Transactions on Image Processing, 1998
- Multi-variate optimal speckle reduction in SAR imageryInternational Journal of Remote Sensing, 1997
- Rice crop mapping and monitoring using ERS-1 data based on experiment and modeling resultsIEEE Transactions on Geoscience and Remote Sensing, 1997
- Change detection techniques for ERS-1 SAR dataIEEE Transactions on Geoscience and Remote Sensing, 1993
- Structure detection and statistical adaptive speckle filtering in SAR imagesInternational Journal of Remote Sensing, 1993