Remote Sensors Glide Into Position
5:26 PM on Dec 27, 2011
Miniature gliders released from an unmanned aircraft dropped from a high-altitude balloon - that was the US Navy Research Laboratory's (NRL) Autonomous Deployment Demonstration (ADD), completed in September but only revealed in December.
The ADD consisted of eight balloon drops at altitudes up to 57,000ft to demonstrate that small, virtually undetectable unmanned air vehicles carrying sensor payloads could be dispersed in selectable patterns, eliminating the need to put remote sensors in place by hand.
The sensor-emplacement vehicle is the NRL-developed Close-In Covert Autonomous Deployment Aircraft (CICADA) Mark III. Two of these tiny gliders were carried under the wing of a UASUSA-built Tempest UAV, which was lifted to altitude by an Aerostar International balloon.
After release at up to 57,000ft and stand-off ranges up to 30nm, the 10.75ft-span Tempest mother ship carried the CICADA vehicles into the target area and released them to glide autonomously to a landing within 15ft of the desired locations, says NRL.
That accuracy was acheived despite the relatively simple vehicle having only a 5Hz GPS receiver and two-axis gyroscope for guidance and control, and no air data sensors, the lab says.
The airframe of the CICADA Mark III is essentially a printed circuit board (PCB) that also serves as the autopilot. This robust construction technique reduces cost and assembly time, NRL says, and allows sensor payloads to be added by changing the PCB design.