Abstract. Main aim of this work is to explore the suitability of high resolution SAR images for measuring ice flow velocity within glaciers. Available techniques for this purpose are Differential SAR Interferometry (DInSAR) and Offset Tracking. The former, although theoretically much more precise, is frequently limited by coherence loss (or lacking of coherence) in glacier environment. The latter constitutes an alternative that works well when displacements are large. Study area is the Viedma Glacier (Santa Cruz, Argentina), one of the largest uncovered ice bodies in the South Patagonian Ice (SPI). High resolution COSMO-SkyMed (CSK) acquisitions were processed by estimating range and azimuth offset fields. Useful results, consisting in displacement maps showing areas with different fast-flowing units, were obtained by Offset Tracking processing.

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Abstract. 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. 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. 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.

Physical changes that occur in land surfaces between two SAR acquisitions affect the precision of repeatpass synthetic aperture radar differential interferometry (DInSAR). This phenomena is defined by the temporal term of interferometric coherence value in each interferometric pair. In this work we carried out an empirical study of the COSMO SkyMed (X-band) temporal decorrelation in both polarization modes, HH and VV. We analysed the polarization effect on the temporal coherence in relation with: 1) percentage of coherent pixels in the regions of interest (ROI), and 2) the seasonal behaviour over the vegetated areas.