UAVs for Science in Antarctica

Remote sensing is a very powerful tool that has been used to identify, map and monitor Antarctic features and processes for nearly one century. Satellite remote sensing plays the main role for about the last five decades, as it is the only way to provide multitemporal views at continental scale. But the emergence of small consumer-grade unoccupied aerial vehicles (UAVs) over the past two decades has paved the way for data in unprecedented detail. This has been also verified by an increasing noticeable interest in Antarctica by the incorporation of UAVs in the field activities in diversified research topics. This paper presents a comprehensive review about the use of UAVs in scientific activities in Antarctica. It is based on the analysis of 190 scientific publications published in peer-reviewed journals and proceedings of conferences which are organised into six main application topics: Terrestrial, Ice and Snow, Fauna, Technology, Atmosphere and Others. The analysis encompasses a detailed overview of the activities, identifying advantages and difficulties, also evaluating future possibilities and challenges for expanding the use of UAV in the field activities. The relevance of using UAVs to support numerous and diverse scientific activities in Antarctica becomes very clear after analysing this set of scientific publications, as it is revolutionising the remote acquisition of new data with much higher detail, from inaccessible or difficult to access regions, in faster and cheaper ways. Many of the advances can be seen in the terrestrial areas (detailed 3D mapping; vegetation mapping, discrimination and health assessment; periglacial forms characterisation), ice and snow (more detailed topography, depth and features of ice-sheets, glaciers and sea-ice), fauna (counting penguins, seals and flying birds and detailed morphometrics) and in atmosphere studies (more detailed meteorological measurements and air-surface couplings). This review has also shown that despite the low environmental impact of UAV-based surveys, the increasing number of applications and use, may lead to impacts in the most sensitive Antarctic ecosystems. Hence, we call for an internationally coordinated effort to for planning and sharing UAV data in Antarctica, which would reduce environmental impacts, while extending research outcomes.info:eu-repo/semantics/publishedVersio

Multi-Temporal investigation of the Boulder Clay Glacier and Northern Foothills (Victoria Land, Antarctica) by integrated surveying techniques

The paper aims to detect the main changes that occurred in the area surrounding the Mario Zucchelli Station (MZS) through analysis of multi-temporal remote sensing integrated by geophysical measurements. Specific attention was directed at realizing an integrated geomorphological study of the Boulder Clay Glacier, a partially debris-covered glacier belonging to the Northern Foothills (Victoria Land, Antarctica). This area was recently chosen as the location for the construction of a new semi-permanent gravel runway for MZS logistical airfreight operations. Photogrammetric analysis was performed by comparing three historical aerial photogrammetric surveys (carried out in 1956, 1985, and 1993) and Very High Resolution (VHR) GeoEye-1 satellite stereo-image coverage acquired in 2012. The comparison of geo-referenced orthophoto-mosaics allowed the main changes occurring in some particular areas along the coast nearby MZS to be established. Concerning the study of the Boulder Clay Glacier, it has to be considered that glaciers and moraines are not steady-state systems by definition. Several remote sensing and geophysical investigations were carried out with the main aim of determining the general assessment of this glacier: Ground Penetrating Radar (GPR); Geodetic Global Positioning System (GPS) network; multi-temporal satellite Synthetic Aperture Radar (SAR) interferometry. The analysis of Boulder Clay Glacier moraine pointed out a deformation of less than 74 mm y-1 in a time span of 56 years, value that agrees with velocity and deformation data observed by GPS and InSAR methods. The presence of unexpected brine ponds at the ice/bedrock interface and the deformation pattern observed in the central part of the moraine has to be monitored and studied, especially under the long-term maintenance of the future runway

Groundwater and Thermal Legacy of a Large Paleolake in Taylor Valley, East Antarctica as Evidenced by Airborne Electromagnetic and Sedimentological Techniques

During the Last Glacial Maximum, grounded ice in the Ross Sea extended into the otherwise ice-free McMurdo Dry Valleys, creating a series of large ice dammed paleolakes. Grounded ice within the mouth of Taylor Valley allowed for lake levels to reach elevations not possible at modern day and formed what is known as Glacial Lake Washburn (GLW). GLW extended from the eastern portion of Taylor Valley roughly 20 km west to a level ~300 m higher than modern day Lake Fryxell. The formation and existence of GLW has been debated, though previous studies correlate the timing of GLW with early Holocene grounded ice. Evidence of GLW has largely been constrained to the interpretation of glacial deposits and fluvial features such as lacustrine deposits, strandlines, and preserved paleodeltas. GIS and remote sensing techniques paired with regional resistivity data provide new insight into the paleohydrology of the region. To quantify the extent of GLW, paleodelta locations were mapped using high resolution LiDAR digital elevation models and satellite imagery. Delta topset elevations were correlated between three streams in Fryxell basin to determine paleolake levels. Additionally, mean resistivity maps generated from airborne electromagnetic survey data (SkyTEM) reveal an extensive groundwater system within Fryxell basin which is interpreted as a legacy groundwater signal from GLW. Resistivity data suggests that active permafrost formation has been ongoing since onset of lake drainage, and that lake levels were over 60 m higher than modern only 1,000 – 2,000 yr BP. This coincides with a warmer than modern paleoclimate inferred by ice core records, indicating a dynamic hydrological system that is highly sensitive to small changes in climate. As global temperatures increase, Lake Fryxell will continue to experience highly variable lake levels. Lakes and groundwater within the McMurdo Dry Valleys are critical to understanding impacts on the broader ecosystem which is largely driven by the availability of liquid water

A New Orbiting Deployable System for Small Satellite Observations for Ecology and Earth Observation

In this paper, we present several study cases focused on marine, oceanographic, and atmospheric environments, which would greatly benefit from the use of a deployable system for small satellite observations. As opposed to the large standard ones, small satellites have become an effective and affordable alternative access to space, owing to their lower costs, innovative design and technology, and higher revisiting times, when launched in a constellation configuration. One of the biggest challenges is created by the small satellite instrumentation working in the visible (VIS), infrared (IR), and microwave (MW) spectral ranges, for which the resolution of the acquired data depends on the physical dimension of the telescope and the antenna collecting the signal. In this respect, a deployable payload, fitting the limited size and mass imposed by the small satellite architecture, once unfolded in space, can reach performances similar to those of larger satellites. In this study, we show how ecology and Earth Observations can benefit from data acquired by small satellites, and how they can be further improved thanks to deployable payloads. We focus on DORA—Deployable Optics for Remote sensing Applications—in the VIS to TIR spectral range, and on a planned application in the MW spectral range, and we carry out a radiometric analysis to verify its performances for Earth Observation studies

Application of UAV BVLOS remote sensing data for multi-faceted analysis of Antarctic ecosystem

A photogrammetric flight was performed in December 2016 as BVLOS (Beyond Visual Line of Sight) operation over Penguin Island (South Shetland Islands, Western Antarctica). Images were taken by the PW-ZOOM fixed-wing UAV equipped with a digital SLR Canon 700D camera. The flight was performed at 550 m ASL and covered a total distance of 231.58 km. The plane takeoff and landing site was near the H. Arctowski Polish Antarctic Station (Arctowski) on King George Island, South Shetlands. The main aim of the mission was to collect environmental data to estimate the size of penguin and pinniped breeding populations and to map vegetation cover and landforms. The plane returned to Arctowski with 1630 images of Penguin Island with the ground sample distance (GSD) lower than 0.07 m. The analysis of developed ortophoto allowed us to locate and identify individuals of two penguin species (Adélie and chinstrap), and individuals of two species of pinnipeds (Southern elephant seal and Weddell seal). Three types of tundra communities were mapped together with numerous landforms such as: volcanic, mass movement, fluvial, coastal and aeolian ones. The UAV BVLOS photogram-metric operation proved to be very robust in gathering valuable qualitative and quantitative data necessary for monitoring distant and isolated polar environments