Atmospheric corrections in interferometric synthetic aperture radar surface deformation – a case study of the city of Mendoza, Argentina
Differential interferometry is a remote sensing technique that allows studying crustal deformation produced by several phenomena like earthquakes, landslides, land subsidence and volcanic eruptions. Advanced techniques, like small baseline subsets (SBAS), exploit series of images acquired by synthet...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2013-09-01
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| Series: | Advances in Geosciences |
| Online Access: | http://www.adv-geosci.net/35/105/2013/adgeo-35-105-2013.pdf |
| Summary: | Differential interferometry is a remote sensing technique that allows
studying crustal deformation produced by several phenomena like earthquakes,
landslides, land subsidence and volcanic eruptions. Advanced techniques,
like small baseline subsets (SBAS), exploit series of images acquired by
synthetic aperture radar (SAR) sensors during a given time span.
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Phase propagation delay in the atmosphere is the main systematic error of
interferometric SAR measurements. It affects differently images acquired at
different days or even at different hours of the same day. So, datasets
acquired during the same time span from different sensors (or sensor
configuration) often give diverging results. Here we processed two datasets
acquired from June 2010 to December 2011 by COSMO-SkyMed satellites. One of
them is HH-polarized, and the other one is VV-polarized and acquired on
different days.
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As expected, time series computed from these datasets show differences. We
attributed them to non-compensated atmospheric artifacts and tried to
correct them by using ERA-Interim global atmospheric model (GAM) data. With
this method, we were able to correct less than 50% of the scenes,
considering an area where no phase unwrapping errors were detected. We
conclude that GAM-based corrections are not enough for explaining
differences in computed time series, at least in the processed area of
interest. We remark that no direct meteorological data for the GAM-based
corrections were employed. Further research is needed in order to understand
under what conditions this kind of data can be used. |
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| ISSN: | 1680-7340 1680-7359 |