AbstractAnalysis of drop size distributions (DSD) measured by collocated Meteorological Particle Spectrometer (MPS) and a third-generation, low-profile, 2D-video disdrometer (2DVD) are presented. Two events from two different regions (Greeley, Colorado, and Huntsville, Alabama) are analyzed. While the MPS, with its 50-μm resolution, enabled measurements of small drops, typically for drop diameters below about 1.1 mm, the 2DVD provided accurate measurements for drop diameters above 0.7 mm. Drop concentrations in the 0.7–1.1-mm overlap region were found to be in excellent agreement between the two instruments. Examination of the combined spectra clearly reveals a drizzle mode and a precipitation mode. The combined spectra were analyzed in terms of the DSD parameters, namely, the normalized intercept parameter N_W, the mass-weighted mean diameter D_m, and the standard deviation of mass spectrum σ_M. The inclusion of small drops significantly affected the N_W and the ratio σ_M/D_m toward higher values relative to using the 2DVD-based spectra alone. For each of the two events, polarimetric radar data were used to characterize the variation of radar-measured reflectivity Z_h and differential reflectivity Z_dr with D_m from the combined spectra. In the Greeley event, this variation at S band was well captured for small values of D_m (<0.5 mm) where measured Z_dr tended to 0 dB but Z_h showed a noticeable decrease with decreasing D_m. For the Huntsville event, an overpass of the Global Precipitation Measurement mission Core Observatory satellite enabled comparison of satellite-based dual-frequency radar retrievals of D_m with ground-based DSD measurements. Small differences were found between the satellite-based radar retrievals and disdrometers.