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Phillips, HA, Allison I, Coleman R, Hyland G, Morgan PJ, Young NW.  1998.  Comparison of ERS satellite radar altimeter heights with GPS-derived heights on the Amery Ice Shelf, East Antarctica. Annals of Glaciology, Vol 27, 1998. 27( Budd WF, Ed.).:19-24., Cambridge: Int Glaciological Soc Abstract

In the spring of 1995 an extensive global positioning system (GPS) survey was carried out on the Amery Ice Shelf, East Antarctica, providing ground-truth ellipsoidal height measurements for the European remote-sensing satellite (ERS) radar altimeters. GPS- and altimeter-derived surface heights have been compared at the intersecting points of the ERS ground tracks and the GPS survey. The mean and rms height difference for all ERS-1 geodetic-phase tracks across the survey region is 0.0 +/- 0.1m and 1.7 m, respectively. The spatial distribution of the height differences is highly correlated with surface topographic variations. Comparisons of GPS-derived surface-elevation profiles along ERS ground tracks show that the ERS altimeters can closely follow the GPS representation of the actual surface.

Fricker, HA, Scambos T.  2009.  Connected subglacial lake activity on lower Mercer and Whillans Ice Streams, West Antarctica, 2003-2008. Journal of Glaciology. 55:303-315. AbstractWebsite

We examine patterns of localized surface elevation change in lower Mercer and Whillans Ice Streams, West Antarctica, which we interpret as subglacial water movement through a system of lakes and channels. We detect and measure the lake activity using repeat-track laser altimetry from ICESat and image differencing from MODIS image pairs. A hydrostatic-potential map for the region shows that the lakes are distributed across three distinct hydrologic regimes. Our analysis shows that, within these regimes, some of the subglacial lakes appear to be linked, with drainage events in one reservoir causing filling and follow-on drainage in adjacent lakes. We also observe changes near ice raft 'a' in lower Whillans Ice Stream, and interpret them as evidence of subglacial water and other changes at the bed. The study provides quantitative information about the properties of this complex subglacial hydrologic system, and a relatively unstudied component of ice-sheet mass balance: subglacial drainage across the grounding line.

Paolo, FS, Fricker HA, Padman L.  2016.  Constructing improved decadal records of Antarctic ice shelf height change from multiple satellite radar altimeters. Remote Sensing of Environment. 177:192-205.   10.1016/j.rse.2016.01.026   Abstract

Antarctica's ice shelves, the floating extensions of the ice sheet, exert an important dynamic constraint on the flow of ice from the grounded ice sheet to the ocean and, therefore, on changes in global sea level. Thinning of an ice shelf reduces its ability to restrain the ice discharge from the grounded ice sheet. However, our understanding of how ice shelf processes couple ice-sheet changes to climate variability is still rudimentary. In part, this is due to the brevity and low temporal resolution of surveys of ice shelf thickness relative to the broad range of time scales on which ice-sheet mass fluctuates. Here, we present improved procedures to construct 18-year (1994–2012) time series of Antarctic ice shelf surface height at high spatial resolution (~30 km) by merging data from three overlapping satellite radar altimeter missions (ERS-1, ERS-2, and Envisat). We apply an averaging scheme to enhance the signal-to-noise ratio of height changes over the floating ice shelves, and extract low-order polynomial trends using a robust approach (regularized regression with cross-validation) that accounts for both bias and variance in the fit. We construct formal confidence intervals by bootstrap resampling of the residuals of the fit. The largest source of height error arises from the interaction of the radar signal with the snow and firn surface; on annual time scales, changes in surface and sub-surface scattering and radar penetration lead to apparent height changes that are larger than the true surface-height change arising from densification. Our 18-year time series of surface height provide an insight into how ice shelves respond to the changing atmospheric and oceanic conditions. Our methods could also be applied to grounded portions of the ice sheets, both in Antarctica and Greenland.