NASA has invested considerable resoruces in deploying a variety of disdrometers,
including: the Two-Dimensional Video Disdrometer (2DVD) by Joanneum Research,
Inc., in Austria; OTT Parsivel Model 2; and Joss-Waldvogel. These instruments
have been deployed in a number of sites, some at
GPM's Wallops Flight Facility
Precipitatioin Research Facility, some at GV sites in Florida,
Kwajalein, other NASA facilities such as GSFC and MSFC/UAH, and still others
deployed or limited periods during Field Campaigns.
These data can be used to generate Drop Size Distributions and integral rain
parameters such as reflectivity, rain rate, liquid water content, DSD drop
statistics such as Dm (median drop diameter), maximum observed drop size,
variance of the drop mass, concentrations and other parameters.