During the MOSAiC expedition, a comprehensive aerial observation program was conducted by the helicopters of the R/V Polarstern. This dataset contains two GeoTiff orthomosaics compiled from aerial RGB images recorded during Leg 4 above the central observatory (CO) on 2020-06-30 and 2020-07-22 and derived surface type classes maps on the leg 4 floe stored in shape file format. The data was processed based on the workflow presented in: https://gitlab.awi.de/nifuchs/pasta-ice. Both orthomosaics were overlaid with the position of the leg 4 floe on 2020-06-30 to facilitate comparison between both. The data is projected to UTM31N (EPSG: 32631) and resampled to a resolution of 0.5m. The aim of this dataset was to retrieve melt pond fraction on the leg 4 floe and give a visual identification for pond locations on both dates.

The orthomosaic RGB orthomosaics are in GeoTiff format with a resolution of 0.5m.The surface type polygons zip-files contains surface type classification in Shapefile format, which were retrieved from the orthomosaics. The attribute tables within these files contain an index column, a column with surface class numbers and a column with surface class names: 0-ponds, 1-snow/ice, 2-open water, 3-submerged ice. The latter is defined as ice covered with liquid water located between snow/ice and open water polygons.