The GPM Ground Validation NASA Autonomous Parsivel Unit (APU) IPHEx dataset was acquired by multiple parsivel instruments during the GPM Integrated Precipitation and Hydrology Experiment (IPHEx), which took place in western North Carolina. IPHEx sought to characterize warm season orographic precipitation regimes, and the relationship between precipitation regimes and hydrologic processes in regions of complex terrain. The APU, an optical disdrometer based on single particle extinction, measures particle size, and fall velocity. ASCII encoded data files contain information on the drop size distribution and integral precipitation parameters such as precipitation rate, reflectivity, and mass-weighted mean diameter.

The GPM Ground Validation Pluvio Precipitation Gauge LPVEx dataset contains both one minute measurements and a cumulative record of the accumulation and intensity of liquid, solid, and mixed precipitation. This dataset was collected during the Light Precipitation Experiment (LPVEx) which was part of the Global Precipitation Measurement (GPM) Misson Ground Validation Experiment which took place in Finland from September 2010 to October 2010. The experiment leveraged in situ microphysical property measurements, coordinated remote sensing observations, and cloud resolving model simulations of high latitude precipitation systems to conduct a comprehensive evaluation of precipitation algorithms for current and future satellite platforms. The campaign will use these measurements to better understand the process of light rainfall formation at high latitudes and augment the currently limited database of light rainfall microphysical properties that form the critical assumptions at the root of satellite retrieval algorithm. Data were collected at three sites: Harmaja, Emasalo, and Jarvenpaa.

The GPM Ground Validation Autonomous Parsivel Unit (APU) GCPEx dataset was collected by the Autonomous Parsivel Unit (APU), which is an optical disdrometer that measures the size and fall velocity of single precipitation particles. The APU consists of the Parsivel (the precipitation measuring instrument), developed by OTT in Germany, and its support systems, which were designed and built by the University of Alabama in Huntsville. The GPM Cold-season Precipitation Experiment (GCPEx) addressed shortcomings in the GPM snowfall retrieval algorithm by collecting microphysical properties, associated remote sensing observations, and coordinated model simulations of precipitating snow. These data sets were collected to aid in the achievement of the over arching goal of GCPEx which is to characterize the ability of multi-frequency active and passive microwave sensors to detect and estimate falling snow. The APU dataset for GCPEx provides precipitation data including raindrop size, raindrop counts, precipitation drop size, precipitation rate, precipitation amount, and snowflake size, counts and distribution. The GCPEx APU data was collected from several sites in Canada during the Winter 2011-2012 period.

The GPM Ground Validation Autonomous Parsivel Unit (APU) MC3E dataset was collected by the Autonomous Parsivel Unit (APU), which is an optical disdrometer that measures the size and fall velocity of single precipitation particles. The APU consists of the Parsivel (the precipitation measuring instrument), developed by OTT in Germany, and its support systems, which were designed and built by the University of Alabama in Huntsville. The APU dataset for the Midlatitude Continental Convective Clouds Experiment (MC3E) provides precipitation data including raindrop size, precipitation drop size, precipitation rate and amount. The Midlatitude Continental Convective Clouds Experiment (MC3E) took place in central Oklahoma during the April-June 2011 period. The experiment was a collaborative effort between the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility and the National Aeronautics and Space Administration's (NASA) Global Precipitation Measurement (GPM) mission Ground Validation (GV) program. The field campaign leveraged the unprecedented observing infrastructure currently available in the central United States, combined with an extensive sounding array, remote sensing and in situ aircraft observations, NASA GPM ground validation remote sensors, and new ARM instrumentation purchased with American Recovery and Reinvestment Act funding. The overarching goal was to provide the most complete characterization of convective cloud systems, precipitation, and the environment that has ever been obtained, providing constraints for model cumulus parameterizations and space-based rainfall retrieval algorithms.

The GPM Ground Validation Precipitation Video Imager (PVI) LPVEx dataset consists of precipitation particle images and drop size distribution (DSD) data collected by the Precipitation Video Imager (PVI) during the Global Precipitation Measurement (GPM) mission Light Precipitation Validation Experiment (LPVEx) field campaign. This field campaign took place around the Gulf of Finland in September and October of 2010. The goal of the campaign was to provide additional high-latitude, light rainfall measurements for the improvement of GPM satellite precipitation algorithms. The PVI instrument was designed by Dr. Larry Bliven at NASA Wallops Flight Facility. Data files are available from September 17, 2010 through May 11, 2011 in Excel format and contain the average, minimum, and logarithmic DSD bin sizes and number of particles per unit time. Browse images are available in BMP and JPG formats.

The GPM Ground Validation Autonomous Parsivel Unit (APU) LPVEx dataset provides rainfall data for the Global Precipitation Measurement (GPM) Misson Ground Validation Experiment collected at four sites in Finland: Harmaja, Emasalo, Jarvenpaa, and the Gulf of Finland (Aranda) during the Light Precipitation Validation Experiment (LPVEx), which took place during September and October of 2010. The experiment leveraged in situ microphysical property measurements, coordinated remote sensing observations, and cloud resolving model simulations of high latitude precipitation systems to conduct a comprehensive evaluation of precipitation algorithms for current and future satellite platforms.

The GPM Ground Validation Precipitation Video Imager (PVI) LPVEx dataset consists of precipitation particle images and drop size distribution (DSD) data collected by the Precipitation Video Imager (PVI) during the Global Precipitation Measurement (GPM) mission Light Precipitation Validation Experiment (LPVEx) field campaign. This field campaign took place around the Gulf of Finland in September and October of 2010. The goal of the campaign was to provide additional high-latitude, light rainfall measurements for the improvement of GPM satellite precipitation algorithms. The PVI instrument was designed by Dr. Larry Bliven at NASA Wallops Flight Facility. Data files are available from September 17, 2010 through May 11, 2011 in Excel format and contain the average, minimum, and logarithmic DSD bin sizes and number of particles per unit time. Browse images are available in BMP and JPG formats.

The GPM Ground Validation Precipitation Occurrence Sensor System (POSS) LPVEx dataset consists of precipitation and radar parameter estimates for both liquid and solid precipitation. Measurements were collected by the Precipitation Occurrence Sensor System (POSS) during the Global Precipitation Measurement (GPM) mission Light Precipitation Validation Experiment (LPVEx) field campaign. This field campaign took place around the Gulf of Finland in September and October of 2010. The goal of the campaign was to provide additional high-latitude, light rainfall measurements for the improvement of GPM satellite precipitation algorithms. The POSS dataset files are available from September 18, 2010 through April 20, 2011 for two POSS sites: Emasalo and Jarvenpaa. The data files are in CSV format with browse imagery in PNG format.

The GPM Ground Validation Autonomous Parsivel Unit (APU) OLYMPEX dataset was collected during the OLYMPEX field campaign held at Washington's Olympic Peninsula during the intense observation period of November 2015 to the end of January 2016. The dataset consists of data collected by 16 APUs. The APU is an optical laser-disdrometer based on single particle extinction that measures particle size and fall velocity. It consists of the Parsivel2 developed by OTT in Germany and supporting hardware developed by University of Alabama. This APU dataset provides precipitation data including precipitation amount, precipitation rate, reflectivity in Rayleigh regime, liquid water content, drop diameter, and drop concentration. Data are available in ASCII format.

The GPM Ground Validation Raw Autonomous Parsivel Unit (APU) IFloodS dataset was collected by 14 Autonomous Parsivel Unit (APU) sites in eastern Iowa during the Global Precipitation Measurement (GPM) mission Iowa Flood Studies (IFloodS) field campaign. The campaign aimed to collect detailed measurements of precipitation at the Earth’s surface using ground instruments and advanced weather radars while simultaneously collecting data from satellites passing overhead. APU is an optical disdrometer system that measures precipitation particle size and fall velocity. This dataset consists of APU-calculated parameters and unfiltered drop spectrum data. The dataset files are available in ASCII text format from April 1 through May 24, 2013. Officially, the IFloodS campaign ran from May 1 to June 15, 2013, but the APUs were installed and had begun collecting data prior to the start of the campaign.