News Articles


New Ultralight Dropsondes Could See Unmanned Missions

NOAA Research/Earth System Research Laboratory - April 24, 2009
Brian Zadler
Brian Zadler, an engineer from Applied Research Associates, Inc., holds a new, ultralight dropsonde. Photo credit: Will von Dauster, NOAA ESRL.

Ultra-light Dropsode
An engineer prepares to test an ultralight dropsonde from atop a 950-foot NOAA tower. Photo credit: Annie Reiser, NOAA ESRL.

On a beautiful, calm March morning in Erie, Colo., NOAA researchers, along with engineers from Applied Research Associates, Inc., watched as palm-sized, bullet-shaped capsules fell from the sky at a brisk 32 feet per second. Just the way they were supposed to.

The new ultralight devices called dropsondes — test-launched from the 950-foot Boulder Atmospheric Observatory tower — are atmospheric data collectors dropped from aircraft that measure air temperature, pressure, relative humidity, and wind speed/direction. Wafer-thin circuit boards inside the devices send the data back to a ground station via radio transmission.

For example, dropsondes are commonly used by "hurricane hunter" aircraft to monitor severe weather conditions.

"We experienced laboratory-like conditions due to the favorable weather," said Russ Chadwick of NOAA's Earth System Research Laboratory. "As the winds picked up, the new dropsondes drifted further to the east with each test drop. They behaved just as we expected they would and the measurements showed this. The test was very successful."

Fitted with long, ribbon-like tails, the new and improved dropsondes weigh less than half as much as current models on the market, and may someday be deployed from ultralight unmanned aircraft systems (UAS).

Eventually, solar-powered UAS, capable of traveling for weeks over remote ocean areas, could carry dozens of ultralight dropsondes to collect environmental data more effectively with less cost.