Abstract: A method of producing an aircraft assembly tool for supporting an aircraft component comprising the steps of: determining the predetermined positions and orientations in space at which the component should be supported; designing a fixture frame to provide support at predetermined locations of the frame associated with said predetermined positions; constructing the fixture frame by selecting elongate members having predetermined lengths and connecting the elongate members together with releasable fasteners; constructing a plurality of pick-up devices, each having a receiving element for carrying the component; mounting the pick-up devices to the fixture frame at the predetermined locations; and moving each receiving element about/around the orthogonal axes to align the receiving element with a respective predetermined position and orientation.

Abstract: This invention relates to a method of calibrating a time-interleaved analogue-to-digital sampler (10) and to a method of performing analogue-to-digital conversion with a sampler (10) so calibrated. The invention provides a method of calibrating a sampler (10) comprising N time-interleaved ADCs (12a–d), the method comprising the steps of: (a) injecting in turn N calibration signals (13) into the sampler such that each calibration signal (13) occupies one of N related frequencies; (b) determining the input signal for each one of the N calibration frequencies (13); (c) measuring in the frequency domain the output at each of the N related frequencies for each one of the N calibration frequencies; and (d) determining the relationship that relates the input signal to the output at each of the N related frequencies for each one of the N calibration frequencies.

Abstract: A method for making a tapered opening. The defined tapered opening is useful for the fabrication of programmable resistance memory elements. The programmable resistance memory material may be a chalcogenide.

Abstract: A head tracker system for determining a user's head orientation relative to a datum (22) comprises: a head mounting (2) for attachment to the user's head; an optical sensor (12) which in use is located in fixed relation with a known fixed point relative to the head mounting (2) and a plurality of distinguishable markings (18a–18j) each of which when in use is located in fixed relation with a respective known point which is fixed relative to the datum (22). The head tracker further comprises an optical correlator (26) for optically correlating the optical image from the optical sensor (12) with an optical image representative of at least one of said markings (18a–18j); and means (28) for determining the orientation of the head mounting using the output from the optical correlator when it detects that there is correlation between the images.

Abstract: A deployable lightning protection apparatus particularly suited for use with an aircraft radome comprises a source of electrically conducting fluid, a deliver apparatus which delivers the conducting fluid flow across to the surface of the radome prior to a lightning strike; and a control unit for controlling the delivery apparatus. The conducting fluid across the outer surface of the radome provides a conductive path for the passage of electrical current resulting from a lightning strike and dissipating said current without damage to the radome. The apparatus allows lightning protection to be deployed in response to a change in atmospheric conditions indicative of a high probability of lightning strike and removed when the danger of lightning strike has passed.

Abstract: A method of and an apparatus for coupling a first optical transmission means (10,42), such as an optical fibre, embedded within an aircraft composite (12,40) to a second optical transmission means (14), such as an optical fibre, external to the composite (12,40) is described. The method comprises locating the position of the first optical means (10,42) embedded within the composite (12,40) using X-ray scanning for example; forming a passageway (20,62) by laser machining or drilling within the composite (12,40) to the first optical transmission means (10,42); and establishing an optical connection between the first and second optical transmission means (10,42,14) at the intersection of the passageway (20,62) and the first optical transmission means (10,42).

Abstract: A selectable mode multi-mode missile carrying submunitions and incorporating guidance and target seeking functions includes triggering or actuation of the submunitions by programming function on the ground or on board another weapon platform or via a link from the ground or said the weapon platform. The submunitions may also be actuated by an impact function. The programming function incorporates or interacts with mode determining or setting devices that cause the missile and its submunitions to selectively operate either in a penetrator mode, a distributed penetrator mode, or in a separation mode. The submunitions are actuated independently, in sequence, or in common with each other depending upon the operating mode selected.

Abstract: A system is provided for determining the type of vehicle which has never been sensed before that is transiting between a cluster of acoustic and seismic sensors by graphing an acoustic source level against a seismic source level for the vehicle, with light vehicles such as pick-up trucks being distinguished from heavy tracked vehicles such as tanks by where on the graph the plotted point for a vehicle lies.

Abstract: A power management system and method of operation is disclosed. The power management system may include a controller associated with each load or subsystem of a plurality of loads or subsystems to determine a lowest operational voltage based on an operating point of the associated load or subsystem. The power management system may further include a voltage link to supply a highest voltage of the lowest operational voltages.

Abstract: One embodiment of the invention is directed to methods and apparatus for determining a variation of a calibration parameter of a pixel of the thermal sensor during operation of the imaging apparatus, after an initial calibration procedure. Another embodiment of the invention is directed to methods and apparatus for calculating a gain calibration parameter using first and second ambient temperature values and respective first and second resistance values for a pixel of a sensor. A further embodiment of the invention is directed to calculating an offset calibration parameter for at least one pixel using a gain of the at least one pixel between first and second times and an ambient temperature at a third time, wherein the pixel is exposed to both scene and ambient radiation at the third time.

Abstract: A non-explosive acoustic source utilizes the combustion of aluminum and water to generate an acoustic pulse. The operation of the non-explosive acoustic source relies on a water/aluminum reaction to generate a burst pressure. The source may be deployed as a single charge or as one element of a multiple charge array and is configurable to explode at variable depths with variable energy levels. The inherent safety of the non-explosive acoustic source obviates the necessity for auxiliary safety features or procedures to protect against inadvertent explosion. As a result, the non-explosive acoustic source facilitates the implementation of sonic detection systems and reduces the operational costs associated with such systems.

Abstract: An interferometer arrangement includes an antenna array that receives radiation from a plane wave emitted by a transmitter, the radiation being incident on the array at an angle (?). The array includes a plurality of antennas that provide output signals to a switching unit. The switching unit selects pairs of signals and passes them to a processor for processing. The processor is configured to produce an output signal that unambiguously indicates the value of the angle (?).

Abstract: Techniques for precise removal of offset charge associated with the reset switch of an integration circuit are disclosed. Offset cancellation circuitry includes a single reset offset subtraction circuit and a replica integrator, which is configured identically to the integrators to be offset cancelled. An offset charge is generated by the circuitry and capacitively coupled to the target integrators. This generated offset charge causes voltage at the input node of each target integrator to substantially match the desired starting voltage level of the targeted integration process. Minimal additional space and circuitry is needed. All of the undesired offset charge is cancelled, without canceling any of the desired input current.

Abstract: A control apparatus comprising a movable control member, a positional servo loop consisting of a motor having a movable armature thereby maintaining the position of the control member at any one of a plurality of positions in a range of movement thereof in accordance with a demand signal, and means for detecting a force applied to the control member and for providing the demand signal which varies in accordance with the magnitude of the applied force, wherein the control member is rigidly attached to the armature so that movement of the control member is precisely mirrored by movement of the armature. The force is detected by measuring the current applied to the motor (which is proportional to the force). Direct drive of the control member eliminates backlash from the system.

Abstract: A hull (11) has mounted thereon a number of accelerometers (20) arranged to provide a data signal corresponding to movement or vibration of the hull (11) to which each is fixed. The hull (11) and/or a thrust block (18) has mounted thereon a number of mass dampers (21) that are controlled by a detector (23) arranged between the accelerometers (20) and mass dampers (21). The detector (23) calculates from the data signal generated by the accelerometers (20) different modes of resonance so as to determine the onset of the excitation of a particular resonance mode and controls the mass dampers (21) so as to generate forces to selectively dampen the resonance mode.

Abstract: A multi-level framework that allows an application to be developed independent of the chip or board, and any dependency is built in as part of the framework of the field programmable device (FPD). A shell configuration called a ‘wrapper’ has a standard look, feel and form factor that provides the interface between the high density language (HDL) application and a standardized and board independent HDL shell, thus isolating the HDL core. A second wrapper is a board specific HDL shell that interacts with the standardized shell. Any application that has the same look, feel and form factor has a common interface that allows various system boards to communicate, providing a mechanism for creating a HDL application component independent of the hardware. An outer shell binds the system to some board and talks to the application program interface (API) layer and the code layer to the outside world, such as the operating system.

Abstract: The system in one embodiment relates to tightly integrating parameter estimation, symbol hypothesis testing, decoding, and rate identification. The present invention provides Turbo-decoding for joint signal demodulation based on an iterative decoding solution that exploits error correction codes. The system iteratively couples an initial amplitude estimator, a symbol estimator, a bank of decoders, and a joint amplitude estimator to produce the symbol estimates.

Abstract: A low radar cross-section monocone antenna is provided with an ultra-wide bandwidth in the microwave region of the electromagnetic spectrum running from 1 gigahertz to 18 gigahertz by decreasing the low frequency cutoff through enlarging the overall dimensions of the cone while at the same time maintaining the base diameter of the apex of the cone to the initially-set dimension that establishes the high frequency cutoff of the antenna. The apex of this cone that serves as its feed point has a base diameter that results in the wide bandwidth, with the monocone antenna having a 5 dBi gain and omnidirectional coverage.

Abstract: A custom made liquid crystal display is formed from a pre-manufactured liquid crystal display by removing an excess region. The drive card is cut along the line X—X and the excess TABs are disconnected from the conductive layer. Optionally, a narrow strip is removed from each of the polarizing substrates between the lines to expose their associated glass plates. A groove is then cut into the exposed surface of each of the glass plates. Each glass plate is then fractured along the base of its groove so that the excess region is detached from the operative region. The cut edges of the glass plates are then sealed by applying a bead of ultra-violet curing adhesive. The processes of removing an excess region by cutting the glass plates with a laser or by freezing the liquid crystal between the glass-plates and machining through the glass plates are also described.

Abstract: Techniques for multiple access differential frequency-hopped spread spectrum (MA-DFHSS) aided by multiuser detection (MUD) are disclosed. An initial DFH decoding is performed to provide data estimates for each user represented in a received co-channel signal. Interference cancellation is then performed using MUD, thereby providing an interference-cancelled signal. Data estimates remaining are then re-decoded. Iteration on the interference cancellation and re-decoding can be carried out to satisfy a particular rule of iteration, although iteration is not always necessary. The final decoded signal can then be provided to its destination.