Bubble Is Watching

GPS Guide to Aerial Surveillance
 Anatomy of a ducted fan unmanned aerial vehicle produced by Allied Aerospace With an ever-increasing appetite to know about people's on-the-ground activities, both foreign and domestic, the U.S. government proves an apt customer for companies developing innovative aerial surveillance platforms. Recent demonstrations launched an aerosphere resembling a gargantuan ping pong ball and ducted fan vehicles that can hover, zoom, or perch on a building ledge. These unmanned vehicles require autonomous navigation, and GPS quite naturally fills the bill.
The SA-60 aerosphere can hover at 16,000 feet, observing 154 square miles beneath it.
AerospheresThe U.S. Navy contracted for tests and evaluation of the SA-60 spherical airship produced by Techsphere Systems International of Atlanta, Georgia, with New Orleans, Louisiana-based Proxity Digital Networks and its subsidiary Cyber Aerospace. The SA-60 low-altitude airship can carry a customer-specified sensor suite for battlefield or homeland surveillance, monitoring warzones or other areas of interest such as borders and ports. As a side benefit to civilian and corporate communities, aerospheres could function as airborne communications platforms for wireless phone and Internet service, filling in wireless "dead zones," and for agricultural and geographical research.
The airship could carry the same types of classified surveillance sensors as satellites and manned or unmanned reconnaissance aircraft: high-resolution cameras, infrared sensors, and over-the-horizon radar. Aerosphere technology could save substantial costs over satellites and aircraft, and provide the advantage of continuous surveillance over a target — called "persistence" — as opposed to intermittent overflight.
Anatomy of a ducted fan unmanned aerial vehicle produced by Allied Aerospace
 GPS-guided ducted fan unmanned aerial vehicle in test flight
The aerosphere would achieve persistence by using GPS to maintain geosynchronous orbit above its target, locking in the coordinates where it needs to stay, tied to an autonomous maneuvering system adjusting to drift and weather patterns. The craft also could use GPS to identify its point of departure for subsequent return and retrieval when running out of fuel or having achieved its mission.
Georeferencing. The designers have not yet implemented GPS navigation in working prototypes but they also envision using GPS to georeference incidents on the ground, giving exact location through integration with onboard observation sensors. The companies may supply and integrate the sensor suite to client specification, or the client may bring and mount them privately.
A June 28 demonstration near Washington, DC, saw the SA-60 climb to 10,000 feet during a three-hour sortie. Powered by four propellers mounted around its circumference and piloted on this occasion by a two-man crew, it used a commercial handheld GPS receiver as a secondary positioning check, and thin-film solar cells, turbodiesel engines, and backup generators to rise and descend.
This model would operate from 5,000 to 15,000 feet and could remain aloft for two days, operating manned or unmanned with up a payload of up to 1,000 pounds.
Other Platforms. The Proxity/Techsphere team produces other aerospheres designed to hover at 2,000 and up to 65,000 feet. The latter forms part of a U.S. Joint Forces Command project dubbed High Altitude, Long Loiter (HALL). Proxity subsidiaries also have designed small, fixed-wing unmanned aerial vehicles, weighing about 10 pounds and transportable by a single soldier or SWAT-team member. With vertical take-off and landing (VTOL) capability, and remote controlled or autonomous GPS/inertial navigation, they could launch from ships, buildings, or street-level, carrying a two-pound payload of explosives or sensors.


Organic Air Vehicles

The Defense Advanced Research Projects Agency (DARPA) launched an Organic Air Vehicle (OAV) program in 2001 and handed contracts to collaborative teams exploring the concept. "Organic" in this sense means owned and operated by the smallest operational field unit, probably a company. The OAV program seeks ultimately to enable battlefield officers to, on their own initiative, launch reconnaissance and surveillance vehicles for such purposes as covert imaging in confined urban areas, biological and chemical agent detection, tagging and targeting, and battle damage assessment. OAVs, by definition small and either man- or vehicle-portable, have VTOL capability and autonomous functioning, requiring little or no operator intervention.
The OAV concept has led to "ducted fan" vehicles that in at least one prototype resemble an old-fashioned outdoor washing machine. Capable of both hovering and cruising, its VTOL feature means it doesn't need a launcher or an airfield. It can autonomously land and provide continuous surveillance from the ground or a building roof or ledge — dubbed "perch and stare" capability — using sensor packages currently available or in development. Operators can remotely order the OAV to move to another station or return to base — these capabilities requiring communication of position coordinates and GPS technology.
Allied Aerospace of Newport News, Virginia has developed several models of UAVs that could function as "organic," field unit-based reconnaissance devices, using their own GPS/inertial flight control system. Dubbed iSTAR for intelligence, surveillance, target acquisition, and reconnaissance, the models have flown at several Space and Naval Warfare Systems Command (SPAWAR) demos, and are scheduled for a Naval Air Systems Command (NAVAIR) presentation in August. The prototypes include one riding aboard an unmanned ground vehicle (UGV) launcher. A GPS/inertial system also controls the UGV.
 OAV on UGV, organic air vehicle aboard an unmanned ground vehicle launcher, both GPS-guided OAV on UGV, organic air vehicle aboard an unmanned ground vehicle launcher, both GPS-guided
The flying vehicles' structure comprises an outer duct enclosing the fan system, centerbody (avionics and subsystems), fixed stators and movable vanes operated by actuators (thrust vectoring). The centerbody houses the engine, and fuel tanks are located in the forward section of the duct. A variety of payloads may be carried in either the nose, tail or duct of the vehicle.
GuideStar. Athena Technologies of Warrenton, Virginia, has also produced miniaturized flight control systems (FCS) for OAV platforms, integrating GPS and inertial navigation. The GuideStar FCS provides a variety of control modes, including airspeed, altitude, climb rate, angle-of-attack, sideslip, 3-D auto-navigation, and automatic takeoff and landing
Manufacturers

Sierra Nevada Corp. will outfit its Proxity SA-60 with a NovAtel Propak GPS receiver. Allied Aerospace's iSTAR flight control system comprises a NovAtel OEM4-G2- RT2W receiver and a Crossbow (San Jose, California) altitude and heading reference system. Athena Technologies' GS 111m flight control system uses u-blox (Thalwil, Switzerland) TIM GPS module and BEI Systron Donner (Concord, California) QRS11 angular rate sensor.




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