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The measurement of accurate full drop size distribution (DSD) is critical for its precise modeling and hydrometeorological application. However, its measurement hinders from instrumental limitation. We explored a way of constructing full DSDs by combining the 2D-Video Distrometer (2DVD) and Meteorological Particle Spectrometer (MPS) measurements based on instrumental uncertainty statistics, while other existing methods use a fixed critical diameter and weighting. First, the median relative bias (RB) of number concentration for each diameter between the two distrometers is used to determine the diameter range of their merging. Second, the weighting factors within the range were derived from normalized standard deviations of MPS and 2DVD number concentration by diameter during quasi-homogeneous microphysical process. The accuracy of derived full DSD is verified with the rainfall rate (R) and radar reflectivity (Z) from other independent instruments such as PLUVIO and Precipitation Occurrence Sensor System (POSS) that provide the best possible reference of R and Z. The new method is superior to the existing methods, providing relatively lower error statistics during summer rainfall events in 2022. Additionally, the impact of the new method is analyzed on DSD variability using double-moment scaling normalization to derive a stable generic function. Four different triple-moment normalization methods are also employed to describe the reduction of DSD variability. The results demonstrate that the new full DSD significantly reduces DSD variability and better provides stable generic function of DSDs. 

We examine several different features of DSDs based on data and observations from two mid-latitude coastal locations: (a) the Delmarva peninsula, USA, and (b) Incheon, South Korea. In each case, the full DSD spectra were obtained from two collocated disdrometers. Two events from location (a) and one event from location (b) are presented. For (a), observations and retrievals from NASA’s S-band polarimetric radar are included in the analyses as well as retrieved DSD parameters from the dual-wavelength precipitation radar onboard the Global Precipitation Measurement satellite. For (b), the disdrometer-based DSD data are compared with measurements from another sensor. Our main aim is to examine the underlying shape of the DSDs and their representation by the generalized gamma model.