Measurement of hail at ground level

The purpose of this study was to measure, with the help of a sensor measuring the impact of hailstones, the physical characteristics of hailfalls point by point, and to extend these measurements to a larger surrounding area. The results of calibrations and data-handling methods, applied to a type of hailpad used in France and Switzerland, are presented. The sources of error resulting from the pad, the natural variability of the hailfalls, and the integration of the data over area are then reviewed.