The DC-8 dropsonde system uses an integrated, highly accurate, GPS-located atmospheric profiling dropsonde, which measures and records current atmospheric conditions in a vertical column below the aircraft. The dropsonde instrument is ejected from a tube in the underside of the DC8 aircraft. As the dropsonde floats to the surface on a parachute, it continuously measures and transmits via a 400 MHz meteorological band telemetry link, pressure, temperature and relative humidity, as well as GPS-based wind formation data, to the receiving system onboard the aircraft. Data was collected for the GRIP campaign from 17 Aug 2010 to 22 Sep 2010. Version 2 was not public.