Abstract: A method for locating and tracking communication units in a synchronous wireless communication system allows for system synchronization and communication unit location when usable GPS signals are not available or are being jammed. Communication units communicate within frames that are synchronized with a timing-reference signal. The timing-reference signal may be generated from GPS signals when available or generated from TOA and trajectory extrapolations when the GPS signals are not available. A disciplined oscillator may be used to maintain substantial synchronization over a few seconds of a frame. In one embodiment, propagation delays of received signals within the frame are determined and provided to other communication units allowing one or more communication units to calculate locations of the communication units. The location information may be reported to the other communication units for use in the self-synchronization.

Abstract: An inflatable structure constructed of flexible material that can occupy a minimal volume when in a deflated and stored condition as compared to its fully inflated and deployed configuration, has sufficient structural rigidity to function as a wing when deployed. The wing includes an array of inflatable chambers with generally circular cross-sections. The chambers are spaced a particular distance between their centers and held in that spacing by an outer wing skin. For equal cross-sectional diameter chambers this distance is less than the diameter. When the chambers are inflated the close spacing causes tension in the opposing surfaces to create a rigid structure.

Abstract: An articulated wing (20) is readily deployable from a stowed configuration that occupies minimal volume to an extended configuration for flight. The wing (20) includes a frame (24) having a pair of beams (30) spaced by one or more ribs (36), and a flexible covering material (26) over the frame (24) that defines the surface of the wing (20). Each beam (30) typically has multiple segments (40), and each segment (40) is pivotally connected to an adjacent segment (40) at a joint (42). A flexible actuation line (52) extends past each joint (42) and is attached to a portion of the beam beyond the joint. The beam (30) also includes portions that act as stops (46). The stops (46) limit the range of angular motion through which the respective segments (40) can rotate relative to one another. Consequently, when tension is applied to the line (52), the segments (40) rotate until respective stops (46) prevent further rotation. Tension in each line (52) keeps the wing (20) in its extended configuration.

Abstract: An unmanned aerial vehicle, such as a remotely-piloted airplane, includes lift-producing wings that have batteries embedded or otherwise located within them. Locating the batteries within the wings allows more efficient use of the interior space of the unmanned vehicle. Space within a fuselage of the vehicle, which would otherwise be used for batteries, may be used for other components. Alternatively, fuselage, weight and/or size of the unmanned aerial vehicle may be reduced. In addition, locating the batteries within the wings may provide better structural performance of the wings, and/or may allow characteristics of the wings, such as inertia and moments, to be optimized.

Abstract: A method for locating and tracking communication units in a synchronous wireless communication system allows for system synchronization and communication unit location when usable GPS signals are not available or are being jammed. Communication units communicate within frames that are synchronized with a timing-reference signal. The timing-reference signal may be generated from GPS signals when available or generated from TOA and trajectory extrapolations when the GPS signals are not available. A disciplined oscillator may be used to maintain substantial synchronization over a few seconds of a frame. In one embodiment, propagation delays of received signals within the frame are determined and provided to other communication units allowing one or more communication units to calculate locations of the communication units. The location information may be reported to the other communication units for use in the self-synchronization.