Two Rain Disdrometers

Two Parsivel disdrometers optically measure particle size and velocity at one-minute time resolution. The size measurement is of the maximum diameter of a one-dimensional particle projection. Measured sizes in theory span 0-25 mm using 32 size classes of varying diameter intervals. The 32 varying velocity categories range up to 20 m/s. The data are binned into size and velocity categories, with hydrometeors assumed to be oblate spheroids. The sample area is 50 cm2. These data are used to establish rain drop size distributions, Z-R relationships, and particle size-fall speed relationships.