{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,15]],"date-time":"2026-01-15T14:07:24Z","timestamp":1768486044115,"version":"3.49.0"},"reference-count":46,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2021,6,20]],"date-time":"2021-06-20T00:00:00Z","timestamp":1624147200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"NASA-GSFC","award":["80NSSC19K0674"],"award-info":[{"award-number":["80NSSC19K0674"]}]},{"DOI":"10.13039\/100006198","name":"Goddard Space Flight Center","doi-asserted-by":"publisher","award":["80NSSC20K0893"],"award-info":[{"award-number":["80NSSC20K0893"]}],"id":[{"id":"10.13039\/100006198","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The Global Precipitation Measurement mission is a major U.S.\u2013Japan joint mission to understand the physics of the Earth\u2019s global precipitation as a key component of its weather, climate, and hydrological systems. The core satellite carries a dual-precipitation radar and an advanced microwave imager which provide measurements to retrieve the drop size distribution (DSD) and rain rates using a Combined Radar-Radiometer Algorithm (CORRA). Our objective is to validate key assumptions and parameterizations in CORRA and enable improved estimation of precipitation products, especially in the middle-to-higher latitudes in both hemispheres. The DSD parameters and statistical relationships between DSD parameters and radar measurements are a central part of the rainfall retrieval algorithm, which is complicated by regimes where DSD measurements are abysmally sparse (over the open ocean). In view of this, we have assembled optical disdrometer datasets gathered by research vessels, ground stations, and aircrafts to simulate radar observables and validate the scattering lookup tables used in CORRA. The joint use of all DSD datasets spans a large range of drop concentrations and characteristic drop diameters. The scaling normalization of DSDs defines an intercept parameter NW, which normalizes the concentrations, and a scaling diameter Dm, which compresses or stretches the diameter coordinate axis. A major finding of this study is that a single relationship between NW and Dm, on average, unifies all datasets included, from stratocumulus to heavier rainfall regimes. A comparison with the NW\u2013Dm relation used as a constraint in versions 6 and 7 of CORRA highlights the scope for improvement of rainfall retrievals for small drops (Dm &lt; 1 mm) and large drops (Dm &gt; 2 mm). The normalized specific attenuation\u2013reflectivity relationships used in the combined algorithm are also found to match well the equivalent relationships derived using DSDs from the three datasets, suggesting that the currently assumed lookup tables are not a major source of uncertainty in the combined algorithm rainfall estimates.<\/jats:p>","DOI":"10.3390\/rs13122412","type":"journal-article","created":{"date-parts":[[2021,6,20]],"date-time":"2021-06-20T21:50:15Z","timestamp":1624225815000},"page":"2412","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Measurements of Rainfall Rate, Drop Size Distribution, and Variability at Middle and Higher Latitudes: Application to the Combined DPR-GMI Algorithm"],"prefix":"10.3390","volume":"13","author":[{"given":"Viswanathan","family":"Bringi","sequence":"first","affiliation":[{"name":"Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, CO 80523, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mircea","family":"Grecu","sequence":"additional","affiliation":[{"name":"Laboratory for Atmospheres and NASA GSFC, Morgan State University, Baltimore, MD 21251, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alain","family":"Protat","sequence":"additional","affiliation":[{"name":"Australian Bureau of Meteorology, Melbourne, VIC 3001, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1458-1814","authenticated-orcid":false,"given":"Merhala","family":"Thurai","sequence":"additional","affiliation":[{"name":"Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, CO 80523, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christian","family":"Klepp","sequence":"additional","affiliation":[{"name":"Max Planck Institute for Meteorology, 20146 Hamburg, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,6,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1118","DOI":"10.1175\/1520-0450(2001)040<1118:TCONDT>2.0.CO;2","article-title":"The concept of \u201cnormalized\u201ddistribution to describe raindrop spectra: A tool for cloud physics and cloud remote sensing","volume":"40","author":"Testud","year":"2001","journal-title":"J. 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