Polar Geospatial Center

The Digital Elevation Models (DEMs) provided here are gridded surface elevation data constructed from overlapping pairs high-resolution (~0.5 m) images acquired by the DigitalGlobe, Inc. Worldview-1 and 2 satellites through the NGA EnhancedView license. The DEMs are built using photogrammetric techniques in which common features are identified in each image and are used to model the relative three dimensional position of the terrain. These DEMs are constructed without ground control and rely on the satellite positioning model (also called the Rational Function Mode, or RFM) to locate the surface in space. The accuracy of the DEM is primarily limited by the accuracy of the rational polynomial coefficients, or RPC’s, used in the RFM model, and is expected to be several meters in the vertical dimension. Additional errors in the DEM arise from failure in the matching software due to clouds, shadows and lack of contrast. Surface Extraction with TIN-based Search-space Minimization (SETSM) from M.J. Noh and I. Howat (Ohio State University) These DEMs were created using the Surface Extraction from TIN-based Search-space Minimization (SETSM) algorithm developed at the Byrd Polar Research Center, Ohio State University with funding from NASA. SETSM uses a pyramiding approach to efficiently generate surfaces from stereo imagery using only the sensor’s Rational Function Model (RFM) and Rational Polynomial Coefficients (RPC). The software is parallelized and runs in the Matlab environment using embedded C-subroutines for efficiency. Noh, M.J., I.M. Howat, Automated stereo-photogrammetric DEM generation at high latitudes: Surface Extraction from TIN-Based Search Minimization (SETSM) validation and demonstration over glaciated regions, GIScience and Remote Sensing, doi:10.1080/15481603.2015.1008621 Ames Stereo Pipeline (ASP) The Flade Isblink DEMs are data products from Flade Isblink, Greenland. The 22 DEMs (2012-14) available showcase the recharge of subglacial lake, evidence through a surficial depression as scene in the DEMs. Desktop Remote Sensing Software (ERDAS, etc.) (currently no data available) © 2012 University of Minnesota.