The GPM Ground Validation Autonomous Parsivel Unit (APU) NSSTC dataset was collected by the Autonomous Parsivel Unit (APU), which is an optical disdrometer based on single particle extinction that measures particle size and fall velocity. This APU consists of the Parsivel, which was developed by OTT in Germany, and its support systems, which were designed and built by the University of Alabama in Huntsville. This dataset provides rainfall data for the Global Precipitation Measurement (GPM) Mission Ground Validation Experiment collected at the National Space Science Technology Center (NSSTC) in Huntsville, Alabama. The validation effort will entail numerous GPM-specific and joint-agency/international external field campaigns, using state of the art cloud and precipitation observational infrastructure. Surface rainfall will be measured by very dense rain gauge and disdrometer networks at various field campaign sites. There may be occasional gaps in the data when the instrument is not resident at the NSSTC and is sent to participate in field campaigns.