Example NetCDF header information for the Hail_size_data: Flight_01_FA_20220628 {dimensions: n = 4901 ;variables: float gsd ; gsd:description = "Ground Sampling Distance" ; gsd:units = "mm/pixel" ; float hail_minor_axis(n) ; hail_minor_axis:description = "Hailstone minor axis length in the image plane"; hail_minor_axis:units = "mm" ; float hail_major_axis(n) ; hail_major_axis:description = "Hailstone major axis lenght in the image plane" ; hail_major_axis:units = "mm" ; int64 hail_center_lightness(n) ; hail_center_lightness:description = "Lightness value of the center hailstone pixel in digital number (DN) ranging from 0-255 (8-bit image depth)" ; hail_center_lightness:units = "DN" ; int64 hail_center_x(n) ; hail_center_x:description = "X-coordinate of the hailstone center pixel within the orthophoto" ; hail_center_x:units = "pixels" ; int64 hail_center_y(n) ; hail_center_y:description = "Y-coordinate of the hailstone center pixel within the orthophoto" ; hail_center_y:units = "pixels" ; // global attributes: :description = "NetCDF file containing hailstone data from a thunderstorm intercepted in Locarno-Monti (Canton Ticino, Switzerland) on 2022-06-28. The data is retrieved from orthophoto Flight_01_FA_20220628.png" ; :author = "Martin Lainer (martin.lainer@meteoswiss.ch)" ;}

Annotation_datasets Test_dataset Expert_A annotations.json (Hailstone annotation data in the COCO JSON format) Expert_B annotations.json (Hailstone annotation data in the COCO JSON format) Training_dataset Expert_A annotations.json (Hailstone annotation data in the COCO JSON format) Images (All tile images 500px x 500px used in the test and training datasets) Orthophoto Flight_01_FA_20220628.png (Full orthophoto of the hail survey area on 2022-06-28) Tiles (435 image tiles generated from the orthophoto with dimension 500px x 500px) Trained_model Evaluation (Data from model evaluations detectron2.evaluation.coco_evaluation) Test Expert_A coco_instances_results.json instances_predictions.pth Expert_B coco_instances_results.json instances_predictions.pth State_dictionary model_final.pth (Final model state as serialized PyTorch state dictionary) Hail_size_data Flight_01_FA_20220628.nc (NetCDF file containing the hail size data from Flight_01_FA_20220628.png)

This hail data collection belongs to a drone hail survey performed on 2022-06-28 in Locarno-Monti (TI, Switzerland). The supercell reached the location around 07:50 UTC in the morning. Only one photogrammetry flight could be performed and thus no estimation of the hail melting process is available.