Multitemporal terrestrial laser scanning point clouds for thaw subsidence observation at Arctic permafrost monitoring sites ...

• Main Authors: Anders, Katharina, Marx, Sabrina, Boike, Julia, Herfort, Benjamin, Wilcox, Evan J, Langer, Moritz, Marsh, Philip, Höfle, Bernhard
• Format: Article in Journal/Newspaper
• Language: English
• Published: Humboldt-Universität zu Berlin 2020
• Subjects: change analysis; 3D geoinformation; ground surface displacement; permafrost monitoring; multitemporal LiDAR; 910 Geografie und Reisen; Ice; permafrost; Tundra
• Online Access: https://dx.doi.org/10.18452/25057; https://edoc.hu-berlin.de/handle/18452/25740

This paper investigates different methods for quantifying thaw subsidence using terrestrial laser scanning (TLS) point clouds. Thaw subsidence is a slow (millimetre to centimetre per year) vertical displacement of the ground surface common in ice-rich permafrost-underlain landscapes. It is difficult to quantify thaw subsidence in tundra areas as they often lack stable reference frames. Also, there is no solid ground surface to serve as a basis for elevation measurements, due to a continuous moss–lichen cover. We investigate how an expert-driven method improves the accuracy of benchmark measurements at discrete locations within two sites using multitemporal TLS data of a 1-year period. Our method aggregates multiple experts’ determination of the ground surface in 3D point clouds, collected in a web-based tool. We then compare this to the performance of a fully automated ground surface determination method. Lastly, we quantify ground surface displacement by directly computing multitemporal point cloud ...