A New Decorrelation Phase Covariance Model for Noise Reduction in Unwrapped Interferometric Phase Stacks
- Creators
- Zheng, Yujie
- Zebker, Howard
- Michaelides, Roger
Abstract
The accuracy of geophysical parameter estimation made with interferometric synthetic aperture radar (InSAR) time-series techniques can be improved with rapidly increasing available data volumes and with the development of noise covariance matrices applicable to joint analysis of networks of interferograms. In this article, we present a new decorrelation phase covariance model and discuss its role in noise reduction in unwrapped interferometric phase stacks. We demonstrate with an example in which we average unwrapped interferogram phase stacks that span over a transient event how a noise covariance model can aid in noise reduction. Our model suggests that, for rapidly decorrelating surfaces (i.e., surfaces with much shorter correlation time than SAR acquisition intervals), it is preferable to incorporate all available interferograms from long observation windows. For slowly decorrelating surfaces (i.e., surfaces with longer correlation time than SAR acquisition intervals), our model suggests that a small subset of interferometric pairs is sufficient. We validate our model and three existing models of decorrelation phase covariance matrices in both Cascadia, a region with heavy vegetation cover, and Death Valley, a desert region with C-band Sentinel-1 A observations. Our proposed model matches observations with the smallest average discrepancy between theory and observations.
Additional Information
© 2021 IEEE. Manuscript received January 15, 2020; revised May 18, 2020, July 27, 2020, October 30, 2020, and December 2, 2020; accepted January 5, 2021. Date of publication January 20, 2021; date of current version November 24, 2021. This work was supported by the NASA Earth Science and Interior Grant NNX 17AE036. The authors would like to thank the anonymous reviewers for their constructive criticisms that greatly improved the quality of this article. Copernicus Sentinel-1 data 2015–2018 was retrieved from ASF DAAC 7 May 2018, processed by ESA, https://www.asf.alaska.edu.Attached Files
Accepted Version - 09329121.pdf
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Additional details
- Eprint ID
- 107637
- Resolver ID
- CaltechAUTHORS:20210121-152557122
- NNX 17AE036
- NASA
- Created
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2021-01-22Created from EPrint's datestamp field
- Updated
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2021-12-14Created from EPrint's last_modified field