UAV-Based Photogrammetry and LiDAR for the Characterization of Ice Morphology Evolution

Abstract

Ice doline is a particular kind of ice morphology, usually scattered on ice streams which are mostly far from the existing research bases. For this reason, glaciologists rarely have opportunities to document its developments in detail. Satellite observations are too coarse to capture such fine features, whereas Unmanned Aerial Vehicle (UAV)-based Structure-from-Motion (SfM) and Light Detection and Ranging (LiDAR) technologies have revolutionized geosciences research, especially in less accessed polar regions. We developed two bespoke UAV systems for glaciological investigation and carried out four campaigns during two consecutive Chinese Antarctic expeditions in 2017 and 2018. Founded on manual co-registration and accuracy assessment, a successful application to characterize a doline's spatio-temporal evolution is presented in this paper. The overlying weight of surface melting directly triggered the collapse event on 30 Jan 2017 near the Dalk Glacier, then the newborn doline grew for another 8135.6 m 2 in area and 280303.38 m 3 in volume by early 2018. The UAV-based results revealed the doline's changes during a year, showing a maximum horizontal extension of 50 m and vertical subsidence of more than 10 m. Furthermore, we evaluate the photogrammetry and LiDAR systems and find the former is cost-effective and time-efficient on a large-scale survey while the latter enjoys a better capability to characterize ice morphological details. Based on systematic comparisons, other pros and cons of the two techniques are discussed. To achieve the best performance for relevant applications in similar scenarios, we recommend adopting an integrated approach, in which the LiDAR restores the fine features on the basis of extensive SfM coverage.

Structures and Deformation in Glaciers and Ice Sheets

“…UAVs also provide an adaptable platform for a wide array of other sensor types (e.g., multispectral, hyperspectral, LiDAR, and photogrammetric stereos), that are increasingly being used for cryospheric research (cf. Gaffey & Bhardwaj, 2020;Li et al, 2020).…”

UAVs for Science in Antarctica

“…The same glacier and event was also analysed by Zhang et al (2019) [98], more focused in obtaining high quality data after UAV surveys than in investigating the causes triggering the catastrophic event. The same group in another study lead by Li et al (2020) [99], incorporated elevation data obtained after UAV surveys with LiDAR (Light Detection and Ranging) to improve the characterisation of the evolution of Dålk glacier. Additional details on the monitoring trough multiple annual surveys with UAV of the same glacier, in a Russian and Chinese collaboration, are reported in Skrypitsyna et al (2021) [100].…”

A Monitoring Method Integrating Terrestrial Laser Scanning and Unmanned Aerial Vehicles for Different Landslide Deformation Patterns

“…These feature points can be extracted manually or calculated automatically by image recognition technology such as Harris corner detection. DOO is widely used in monitoring of slow ground movement, such as glacier and ice cap [27], [43], [51], [52]. In this study, we superimposed registered UAV orthophotos in different period and changed their color bands to show the horizontal difference of the landslide (Figs.…”

“…For example, GB-SAR can accurately identify the slope deformation of a few millimeters in several seconds [24], and the distance between the point clouds obtained by TLS can reach a few millimeters [25], [26]. Comparatively, the monitoring range and accuracy of airborne remote sensing technologies are between the spaceborne and ground-based devices [27], and the flexibility and high adaptability to complex terrain make it play an irreplaceable role in data acquisition, deformation monitoring and landslide susceptibility mapping [28]- [32].…”