The GPM Ground Validation DC-8 Navigation and Housekeeping Data GCPEx dataset, which is composed of two types of files. GCPEx addressed shortcomings in the GPM snowfall retrieval algorithm by collecting microphysical properties, associated remote sensing observations, and coordinated model simulations of precipitating snow. National Suborbital Education and Research Center (NSERC) of the University of North Dakota (UND) provided geo-located housekeeping data containing attributes, such as altitude, pressure, air speed, and wind speed. The NASA DC-8 Navigation data in comma delimited IWG1 format were collected and utilized in-flight during the GCPEx mission and retrieved from the Real-Time Mission Monitor. Both file types are available for most of the dataset dates, however please note that there are a few dates where only the IWG1 formatted data is available.