The Naval Research Laboratory is taking a cue from nature in developing unmanned surveillance aircraft that don't use much power to stay aloft for hours at a time—and still communicate with each other to work in concert.
Working with the Air Vehicle Intelligence and Autonomy Lab at Pennsylvania State University, NRL has tested a cooperative autonomous soaring algorithm, called the Autonomous Locator of Thermals (ALOFT) autonomous soaring algorithm, that can keep sailplanes airborne for much longer that previously possible, NRL said in a release.
The tests, in restricted airspace at Phillips Army Airfield, Aberdeen Proving Grounds, Md., consisted of pairs of unmanned sailplanes using thermal updrafts to stay in the air and sharing soaring data between them in flight. "Autonomous soaring algorithms seek out naturally occurring areas of rising air called thermals," Dr. Dan Edwards, aerospace engineer and principle investigator of the solar-soaring program, said. "Cooperative autonomous soaring combines data from multiple autonomous soaring aircraft to make a more complete measurement of the local atmospheric conditions. This atmospheric map is then integrated to guide both aircraft toward strong lift activity quicker than if it was just a single aircraft, a technique very similar to that used by a flock of soaring birds."