UAV

Spring UAV Campaign

1 April 1999 - 31 May 1999

Lead Scientist: Tim Tooman

Observatory: OSC

The Department of Energy’s Atmospheric Radiation Measurement - Unmanned Aerospace Vehicle (ARM-UAV) Program was established with the objectives of demonstrating the utility of UAVs for atmospheric research and fostering the development of instruments and measurement techniques suitable for use on UAVs. From the outset, these objectives were pursued in the context of obtaining important scientific data at various locales, in particular at DOE ARM sites in the Southern Great Plains (SGP), North Slope of Alaska, and Tropical Western Pacific. The ARM-UAV program is now transitioning to a more operationally oriented program with the objective of conducting regular high altitude airborne measurements at ARM sites. The ARM-UAV Program was initiated as part of the larger DOE objective of improved understanding of the role of clouds in global climate change. One component of that DOE objective is addressed by the ARM Program, emphasizing long-term ground-based measurements of cloud and atmospheric properties, and the ARM-UAV Program, emphasizing airborne measurement campaigns primarily using UAVs but also using piloted aircraft when appropriate. The long-term ARM-UAV goal of making measurements at the top of the troposphere in the tropics resulted in the requirement for a long endurance UAV capable of carrying an instrumented payload to altitudes above 60,000 feet. To date, ARM-UAV flights have been conducted with General Atomics - Aeronautical Systems “GNAT” and “Altus” UAVs and instrumented Grob “Egrett” and DOE “Twin Otter” piloted aircraft. From its inception in 1993 to date, the ARM-UAV Program has accomplished 9 major field measurement campaigns. The majority of these have been conducted as part of Intensive Observing Periods at the SGP Cloud and Radiation Testbed (CART) site in north-central Oklahoma. However, flights have been conducted at other locations, including a cirrus cloud campaign conducted at altitudes up to 57,000 feet at Kauai, HI, in 1999. In the course of the ARM-UAV program, a number of notable accomplishments have advanced the state of the art in airborne measurements and demonstrated the utility of UAVs. These accomplishments include the first science flights using a UAV in 1994, the first use of an unescorted UAV in general use airspace in 1996, the development of a GPS-based system that allows precise vertically stacked flight of a UAV and a piloted aircraft for cloud absorption measurements, a data-taking flight of over 26 hours in duration over the CART site, and the development of several compact instruments suitable for UAV applications.