Abstract: A stationary, lightweight, easily transportatable antenna capable of full duplex operation, i.e., portions of the antenna can transmit and receive simultaneously in the same frequency band. The antenna has a near omnidirectional pattern in the azimuth plane for both transmit and receive. The receive portion (2) consists of four antenna elements (20), each having a beamwidth in the azimuth plane slightly greater than 90.degree.. The receive antennas (20) are arranged symmetrically about a midpoint (93) that lies in the azimuth plane. The beams of the four receive antennas (20) face outwardly away from the midpoint (93) and thereby cover the full azimuth plane. The transmit portion (1) of the antenna is a colinear set of dipole elements (12) arranged within a cylinder (11) that is orthogonal to the azimuth plane and centered on said midpoint (93).

Abstract: Edge definition in FLIR images is improved by assigning to each pixel (X) the average intensity value of that 3.times.3 pixel sub-matrix (30a-30i) containing the pixel (X) which exhibits the smallest edge value. Apparatus for obtaining that intensity value in real time is disclosed. This process can be iteratively repeated on the same image, with each iteration creating more enhanced edges and greater area smoothing between edges.

Abstract: A cascadable seventeen-bit self-testing comparator (20) is produced on a twenty-four pin GAL.RTM. 39V18 generic array logic chip by so interconnecting the data pins (1-17) with the logic macro cells (24a-h, 26a-i), and configuring the macro cells, that any data applied to the pins is registered in the macro cells (24a-h, 26a-i) upon pulsing the clock (35), and any exact coincidence of subsequent data with the registered data causes one of the macro cells (26j) to generate a match-indicating output (61).

Abstract: The efficiency of a metal silicide infrared detector (10) in greatly enhanced by depositing on the substrate (14) a stack (30) of alternating metal silicide (12,24) and silicon layers (22). The metal silicide layers (12,24) are connected to each other and to a contact pad (20) in the substrate (14) by a metal silicide deposit (32) on one side of the stack (30) and the silicon layers (22) are connected to each other and to the substrate (14) by a silicon deposit (34) on another side of the stack (30). The stacking of layers is made possible by depositing the silicon layers (22) at a rate of 1 .ANG./sec or less in a vacuum of 10.sup.-9 torr or better at a temperature of about 250.degree. C.

Abstract: Information-theoretic notions are employed to establish the predictability of a random number generated from a circuit exhibiting chaos in order to obtain a number from a sequence of numbers with a known level of randomness and security. The method provides a measure of information loss whereby one may select the number of iterations before or between bit sampling in order to extract a secure pseudo-random number. A chaotic output is obtained by use of a sample and hold circuit coupled in a feedback loop to a variable frequency oscillator, such as a voltage controlled oscillator circuit, and operated with a positive Lyapunov exponent. A source signal generator, such as a periodic wave generator, provides a driving signal to the sample and hold circuit.

Abstract: An erectable structure truss attachment joint includes a first truss having a casing containing a piston between a flange on the end of the casing and a wedge threadably mounted on an adjustment screw inside the casing. A tension rod passing through the wedge and the piston has a knob extending out of the casing on one end and an end bolt holding a leaf spring against the wedge on the other. A helical spring inside the casing creates pressure between the piston and the tension rod. A second truss has a notched retention wall at one end forming a chamber. The knob of the tension rod is inserted into the chamber to attach the two trusses. When the adjustment screw is tightened, the wedge acts against angled faces of the leaf spring on one side and the piston on the other side to create pressure against the piston and the leaf spring. The leaf spring exerts pressure against the end bolt to pull the tension rod into the interior of the casing.

Abstract: A mid-air aerial recovery system comprising a payload, a parachute, and an aerial engagement apparatus. The parachute is connected to the payload. The parachute has a sufficient size to support the weight of the payload. The parachute has a plurality of suspension lines extending from the payload to a canopy of the parachute. The aerial engagement apparatus is a loop rope fastened to the parachute and extending outwardly beyond the canopy of the parachute. This loop rope forms a reception area. The parachute is a ram-air parachute. The loop rope is fastened at one end to the payload and extends along the suspension lines of the parachute and is attached to a leading edge of the canopy.

Abstract: An arrangement that uses aircraft fuel as a heat sink for aircraft auxiliary oil systems for an aircraft having at least one engine operated by fuel and having an engine interface limit and including a fuel/oil heat exchanger for removing heat from the aircraft auxiliary oil systems and having a fuel outlet temperature, a temperature sensing for determining temperature of the fuel leaving the fuel/oil heat exchanger, a recirculating flow control valve having variable positions including an open and a closed position controlled by the temperature sensor, the fuel always going to the aircraft engine but also going through the flow control valve when the flow control valve is in the open position so that recirculation is minimized and maximum heat is rejected to the engine by the fuel outlet temperature of the fuel/oil heat exchanger when the fuel outlet temperature of the fuel/oil heat exchanger is controlled by the engine interface limit, a ram air heat exchanger for removing heat from the fuel leaving the rec

Abstract: A collector for a liquid drop radiator for cooling at least one fluid droplet stream. The collector has a housing with at least one inlet for the at least one fluid droplet stream and one outlet and lies in a plane, and a pump disposed in the housing and which has a low pressure side and lies in a plane which is the same as the plane that the housing lies in. The at least one inlet of the housing converges towards the pump so that the at least one fluid droplet stream is directed towards the low pressure side of the pump and directed by the pump to the outlet of the housing.

Abstract: A torque joint for transmission of force in both longitudinal and circumferential direction about thin-wall tubular torque tubes is provided by overlapping an inner one of said tubes and an outer one of said tubes, inserting a mandrel having longitudinal and circumferential slots therein, applying a deformation force for pressing the tubular members into the slots of the mandrels, and extracting at least a portion of the mandrel to provide the torque joint. In the case wherein two open-ended tubular members are employed, two mandrel elements of the same form are utilized, the two mandrel elements being withdrawn from the opposite ends of the joint upon completion of assembly of the joint. In the event that one of the tubular elements is closed ended, a retaining ring is utilized as one of the mandrel elements, in which case only one mandrel element is withdrawn while the ring remains captured between a circumferential groove of the joint and the closed end of the tube.

Abstract: A system for sensing and annunciating the presence at any one of a plurality of locations of accumulations of potentially hazardous gaseous and vapor mixtures prior to their reaching a lower explosive limit thereof. The system has particular applicability to aircraft, and has a number of advantageous features such as adjustable annunciator set points which are settable between relatively wide lower explosive level limits, compensation in the sensor circuitry for temperature variations, built in diagnostic and test features, and a circuit design wherein multiple sensors at multiple locations are operable independently of each other.

Abstract: In a wind turbine assembly incorporating a diffuser, the diffuser includes an articulated duct formed of a set of members, such as the sectors of a conic section, which are pivotable about axes in a plane normal to the turbine axis. To permit an enlargement or contraction of the articulated duct, the members are joined by flexible gussets or, alternatively, are configured for overlapping. Springs offset from the pivoting axes are attached to the members to provide a bistable attitude thereto. In response to high winds, the spring forces are overcome by the wind forces on the articulated duct to allow the members to pivot inwardly reducing the effective wind capture area of the diffuser. The diffuser is further fabricated with slots between sections of duct to enlarge the effective area swept by the turbine blades for increased power availability from the turbine.

Abstract: An automatic digital gain ranging system wherein the zeros are eliminated preceding the most significant nonzero bit and the shortened encoded word that results includes a gain code designation according to the number of zeros eliminated plus a predetermined number of data bits determined in accordance with the position of the most significant nonzero bit.

Abstract: A continuous film having a solar selective coating on one surface and adhesive on the opposite surface is produced by a coil type process. The film may be cut to size and shape for application to solar collectors.