The Greenland Ice Sheet, now in HD

Abstract:

We are constructing very-high resolution (2 m of the margin, 10 m of the interior) Digital Elevation Model (DEM) and orthoimage mosaics of the the Greenland Ice Sheet from stereoscopic-mode satellite imagery acquired by the Worldview constellation and archived at the Polar Geospatial Center. The DEMs are constructed with the fully-automated Surface Extraction from TIN-based Search Minimization (SETSM) software developed by Ohio State University specifically for DEM extraction over high latitude terrains. The SETSM algorithm features an iterative process for correcting biases in the imagery geolocation information, improving DEM success over low-contrast and repetitively-textured surfaces such as snow and mountain shadows. The imagery are orthorectified using the corresponding DEM and individual orthoimages and DEMs are mosaiced into continuous tiles of coverage. To facilitate change detection, each pixel contains an acquisition date stamp and a flag indicating if the DEM pixel was measured or interpolated. The data are openly available online with registration at http://www.pgc.umn.edu/elevation/stereo .

Here we present the Greenland DEM and orthoimage mosaics with examples of applications and comparisons to existing datasets. We compare the DEM’s to coincident laser altimeter measurements to examine accuracies and potential biases, as well as discuss the feasibility of merging the DEMs with coordinated laser altimeter surveys to improve the spatial coverage of high-precision elevation data.