Helicopter-borne RGB orthomosaics and photogrammetric Digital Elevation Models from the MOSAiC Expedition

• Main Authors: Neckel, Niklas, Fuchs, Niels, Birnbaum, Gerit, Hutter, Nils, Jutila, Arttu, Buth, Lena, von Albedyll, Luisa, Ricker, Robert, Haas, Christian
• Format: Dataset
• Language: English
• Published: PANGAEA 2023
• Subjects: 20200321_01; 20200423_01; Arctic Ocean; Binary Object; Binary Object (File Size); Event label; HELI; Helicopter; MOSAiC; MOSAiC20192020; MOSAiC expedition; Multidisciplinary drifting Observatory for the Study of Arctic Climate; Polarstern; PS122_4_44_78_2020061601; PS122_4_45_112_2020070401; PS122_4_45_36_2020063001; PS122_4_45_37_2020063002; PS122_4_46_36_2020070701; PS122_4_46_39_2020070703; PS122_4_46_97_2020071101; PS122_4_47_96_2020071701; PS122_4_48_69_2020072201; PS122_4_50_32_2020080601; PS122/3; PS122/3_32-42; PS122/3_32-70; PS122/3_33-17; PS122/3_37-63; PS122/3_37-66; PS122/3_39-109; PS122/4; PS122/4_44-78; PS122/4_45-112; PS122/4_45-36; PS122/4_45-37; PS122/4_46-36; PS122/4_46-39; PS122/4_46-97; PS122/4_47-96; PS122/4_48-69; PS122/4_50-32; PS122/5; PS122/5_59-139; PS122/5_61-190; PS122/5_61-62; PS122/5_61-63; PS122/5_62-166; PS122/5_62-67; PS122/5_63-3; Sea ice
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.949433; https://doi.org/10.1594/PANGAEA.949433

The Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition took place between October 2019 and September 2020 giving the rare opportunity to monitor sea-ice properties over a full annual cycle. Here we present 24 high-resolution orthomosaics and 14 photogrammetric digital elevation models of the sea-ice surface around the icebreaker RV Polarstern between March and September 2020. The dataset is based on >34.000 images acquired by a helicopter-borne optical camera system with survey flights covering areas between 1.8 and 96.5 km^2 around the vessel. Depending on the flight pattern and altitude of the helicopter, ground resolutions of the orthomosaics range between 0.03 and 0.5 m. By combining the photogrammetric products with contemporaneously acquired airborne laser scanner reflectance measurements selected orthomosaics could be corrected for cloud shadows which facilitates their usage for sea-ice and melt pond classification algorithms. The presented dataset is a valuable data source for the interdisciplinary MOSAiC community building a temporal and spatially resolved baseline to accompany various remote sensing and in situ research projects. Central Observatory (CO) grid flights are available as single grids while transect and triangle flights were segmented into 2 km x 2 km data tiles to provide the user with manageable file sizes. Next to the orthomosaic and DEM data we provide confidence maps of the respective survey flights. All data is stored in GeoTIFF file format and gridded to 0.5 m spatial resolution. For the CO grid flights we also provide orthomosaic data at full spatial resolution within a 3 km square centered at Polarstern. The naming convention of the final data products is: Date, #Flight, DShip ID, followed by DEM, confidence or orthomosaic, and hr for high resolution (0.5 m) or fr for full resolution. As we provide brightness corrected orthomosaics these are termed l2 for level 2 products and if the data were corrected for the effect of cloud shadows we ...