On the errors involved in ice-thickness estimates II: errors in digital elevation models of ice thickness

• Published in: Journal of Glaciology
• Main Authors: J. J. LAPAZARAN, J. OTERO, A. MARTÍN-ESPAÑOL, F. J. NAVARRO
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2016
• Subjects: DEM; error analysis; ground-penetrating radar; glacier mapping; ice thickness; Environmental sciences; GE1-350; Meteorology. Climatology; QC851-999; Svalbard; Werenskioldbreen; glacier; Journal of Glaciology
• Online Access: https://doi.org/10.1017/jog.2016.94; https://doaj.org/article/ff8eeed1da9f45fd96419e7c5087504a

This paper is the second (Paper II) in a set of studies concerning the errors involved in the estimate of ice thickness and ice volume. Here we present a detailed analysis of the errors involved in the generation of ice-thickness DEMs constructed, most often, from GPR data, complemented by boundary data and sometimes, additional synthetic data arising from estimates based on theoretical considerations supported by independent data. We describe a complete methodology of error analysis that, starting from the errors in the data, propagates them to the grid nodes. In turn, the interpolation error at the grid nodes is calculated using a novel procedure that also provides an estimate of the bias introduced by the interpolation process. Finally, both errors are combined at the grid nodes to produce a gridpoint-dependent error estimate, which is complemented by an overall error estimate providing an assessment of the quality of the DEM. This methodology is illustrated with the case study of Werenskioldbreen, a land-terminating polythermal glacier in Svalbard.