Uncertainty in Digital Elevation Models of Axel Heiberg Island, Arctic Canada

Abstract We analyze errors in several digital elevation models (DEMs) of part of Axel Heiberg Island, Nunavut, Canada. We define total error as the sum of map-reading error, which measures the fidelity of the DEM to the map, and mapping error, which measures the fidelity of the map to the terrain. Three of the DEMs derive from estimates made by eye on maps prepared for research purposes and having scales of 1:10,000 (“10K”), 1:50,000 (“50K”) and 1:100,000 (“100K”), while two are based on spatial interpolation from published topographic maps of scale 1:250,000 (“250K”) and 1:1 000,000 (“1M”). Map-reading errors are reduced markedly by proofreading, and are unbiased but not normally distributed. They are also moderately correlated, with decorrelation distances of 1 to 3 DEM resolution elements. Replicate readings from maps 10K and 50K have rms differences of about 20 m, a figure which shrinks to 12 m when gross errors are identified and excluded. These differences represent the mapping errors. Total error i...