Abstract
Abstract. We have developed a new digital elevation model (DEM) of Antarctica from a combination of satellite radar and laser altimeter data. Here, we assess the accuracy of the DEM by comparison with airborne altimeter data from four campaigns covering a wide range of surface slopes and ice sheet regions. Root mean squared (RMS) differences varied from 4.75 m, when compared to a densely gridded airborne dataset over the Siple Coast region of West Antarctica to 33.78 m when compared to a more limited dataset over the Antarctic Peninsula where surface slopes are high and the across track spacing of the satellite data is relatively large. The airborne data sets were employed to produce an error map for the DEM by developing a multiple linear regression model based on the variables known to influence errors in the DEM. Errors were found to correlate highly with surface slope, roughness and density of satellite data points. Errors ranged from typically ~1 m over the ice shelves to between about 2 and 6 m for the majority of the grounded ice sheet. In the steeply sloping margins, along the Peninsula and mountain ranges the estimated error is several tens of metres. Less than 2% of the area covered by the satellite data had an estimated random error greater than 20 m.
Highlights
Digital elevation models (DEMs) of the Antarctic are important datasets for a wide range of applications from fieldwork planning, calculating drainage basins, calculating mass balance, determining balance velocities to dynamical modelling of the ice sheet (Budd and Warner, 1996; Remy et al, 1999; Rignot et al, 2008; Smith et al, 2006)
Biases are shown to close to zero for all surface slopes surveyed with random errors being about half those from older DEMs based on ERS data only (Bamber and GomezDans, 2005) and between 7 and 30% smaller than those for the DEM containing only GLAS data
When compared to the most widespread airborne dataset (SOAR CASERTZ), which covers a range of surface slope and roughness, a bias of 21cm and random error of 4.75 m are seen
Summary
Digital elevation models (DEMs) of the Antarctic are important datasets for a wide range of applications from fieldwork planning, calculating drainage basins, calculating mass balance, determining balance velocities to dynamical modelling of the ice sheet (Budd and Warner, 1996; Remy et al, 1999; Rignot et al, 2008; Smith et al, 2006). We assess the accuracy of our new DEM using a range of extensive airborne altimeter data sets covering both East and West Antarctica, interior plateau regions, marginal areas and ice shelves. As this validation only has limited spatial extent, the results of this comparison were used to calculate an error map for the entire continent. This means that, for the first time, a user of a DEM of the entire Antarctic ice sheet can do so with full knowledge of the size of the error on that measure and its full spatial variability. Bamber: A new Antarctic digital elevation model: validation and error estimates
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
