A small, unmanned aerial vehicle (UAV) has made test flights over the world’s largest vineyard in California on August 19 to prepare for nighttime frost studies for annual grape yields early next year. The UAV – a remotely piloted aircraft – is bigger than a model airplane but smaller than a light plane. NASA, university and industry teams are testing the UAV, its imaging and other data-collecting systems, as well as preparing the test team. The test flights took place over San Bernabe Vineyard, which is located just west of King City and midway between two California cities, Salinas and Paso Robles-about 50 miles from the two.
“We are developing wireless operation of a new sensing device that will remotely gauge temperature and other conditions while flying over the grapes,” said Stanley Herwitz, director of the Clark University UAV Applications Center at NASA Research Park, and professor of Earth science from Clark University, Worcester, Mass. Frost damage could decrease annual grape yields by more than 50 percent, according to Hoover. Such a decrease would amount to a loss in revenue of more than $12,000,000 for this vineyard alone. The UAV airplane transmits thermal images and GPS information to be overlaid on irrigation maps, showing how the small UAV can help grape growers monitor frost in large areas of vines. This technology also may be useful for monitoring orchards and other frost-sensitive crops. The UAV’s infrared camera systems are calibrated to read out temperature directly.
Thermal images from the UAV showing temperature trends and rates of change will help vineyard managers to make key decisions about the timing of irrigation treatments. Smaller UAVs, like the one to be flown during the grape test missions, cost less than larger UAVs. In addition, recent advances in navigation systems make small UAVs easier to fly.A wireless computer local area network (LAN) operating in the unlicensed 900 Mhz radio band provided instrument control and data downlink of images and other information at up to a 75-kilometer (almost 50-mile) range.Researchers will share the results of their March-to-May 2004 UAV frost-detection mission at the annual meeting of the California Vintners’ Association.