Abstract: A method and system is described for reducing unwanted noise components/interfering targets detected through an ambiguous beam-steer direction, such as the ambiguous ‘back-lobe’ of a sensor array. A pressure sensor array 52 and a plurality of pressure gradient sub-arrays 541-N are beamformed individually at processing stages 56, 581-N to derive signals indicative of directional responses, one from each group or sub-group. The signals are scaled and weighted (60, 620-N) and processed to define a cardioid beam with nulls pointing in the ambiguous beam-steer direction.

Abstract: A system and method for secure transport of data, the method comprising: sharing of key information with a key distributor, wherein the key information is for enabling decryption of first and second encrypted data, the key distributor being for making one or more decryption keys available to an authorised user; creating a container object, the container object comprising: first encrypted data having a first encryption based on at least a part of said key information; second encrypted data having a second encryption based on at least a part of said key information, wherein the first encryption is different to the second encryption; and metadata relating to the first encrypted data and the second encrypted data; and sending the container object to a data store or otherwise making the container object available, to allow user access to said data container object.

Abstract: A continuous wave frequency shift-keyed radar apparatus comprising means for changing the frequency of the transmitted continuous wave periodically and in a pseudo-random sequence, means for mixing the received wave with the transmitted wave or a delayed version thereof to produce a beat signal, means for sampling the beat signal, in respect of each period of simultaneous transmission and reception at the same frequency, means for reordering successive segments of the sampled beat signal to put them in sequential frequency order, and means for transforming the reordered segments to provide an output signal in the range domain.

Abstract: A warning unit for attachment to a handheld firearm comprises attachment means for attachment to a firearm, a light source, and digitally manipulable input means operable to enable selection of a mode of operation. The warning unit is capable of being operated in at least a narrow divergence mode, and a wide divergence mode wherein, in the narrow divergence mode, the warning unit is operable to emit a beam of light of a lower divergence than in the wide divergence mode.

Abstract: A radio apparatus comprising: a radio frequency processing module for converting radio frequency signals from an antenna to intermediate frequency signals; an intermediate frequency processing module located remotely from the radio frequency processing module, for receiving intermediate frequency signals and processing said signals according to at least one communications protocol; and a digital data link for connecting the radio frequency processing module and the intermediate frequency processing module, for transfer of the intermediate frequency signals.

Abstract: An apparatus for towing behind an underwater vehicle has a body and a yoke pivotally connected to the body at a pivot point and having a tether remote from the pivot point by which the apparatus us towed. The yoke has wings which generate a resultant force on the body when the apparatus is towed. By varying the orientation of the yoke relative to the body, the magnitude of the resultant force may be varied. The resultant force tends to reduce the displacement of the tether relative to the pivot point in at least one plane, thereby generating a force to counter the buoyancy of the apparatus, and so stabilize the apparatus when it is being towed.

Abstract: The present invention relates to a motion classification device 14 comprising sensor means 141 for monitoring movements of a targeted object, said sensor means 141 being operable to output motion signals based on said monitored movements, a processing means 147 for processing said motion signals, said processing means being operable to compare said processed motion signals with a set of predetermined values such that an event of said targeted object 12 being moved from a first mode of operation to a second mode of operation can be detected by determining the difference between said processed motion signals and said set of predetermined values.

Abstract: A signal processing system for use in pulse-Doppler radar, arranged to receive frequency domain signals for each of a plurality of Doppler bins for each range cell, comprising a data processor arranged successively to threshold each Doppler bin signal under test relative to a local average of signals formed over plural Doppler bins and/or plural ranges adjacent to the Doppler bin under test, using a variable thresholding factor, and using the thresholding result as an indication of the presence of an object of interest; the data processor using a pulse-Doppler constant false alarm rate control process to set and reset the variable thresholding factor using closed loop feedback by counting the indications of presence and incrementing or decrementing the variable thresholding factor for each thresholding result by comparing the frequency of these counts with a predetermined probability of false alarms; whereby the constant false alarm rate thresholding is a function of the range and the Doppler frequency of the

Abstract: An air vehicle comprising only one wing, which is thin and substantially flat, the wing being elongate and preferably diamond-shaped, and a pod removably coupled to the wing for relative rotation about an axis normal to the major surfaces of the wing, the pod bearing a propulsor for the air vehicle. The propulsor may be a propeller with a Custer duct for static lift.

Abstract: An integrated circuit package comprising at least two printed circuit boards each comprising a substrate coated with metallic layers on both sides and having plated through-holes for electrical and thermal connection to the metallic layers, at least two of the printed circuit boards being diffusion-bonded at an interface between their respective metallic layers, the bonded metallic layers forming an hermetic seal between the opposed external surfaces of the integrated circuit package.

Abstract: A scan-to-scan integrator for use in radar apparatus comprises means for defining a search window for use in verifying a candidate detection. The window is bounded by the intersection of a first zone and a second zone, wherein the first zone comprises a rectangular reference frame aligned detection window, and the second zone comprises a range estimate tolerance region defined by a range estimate for the candidate detection and predetermined tolerance limits.

Abstract: A strip-map Synthetic Aperture Radar (SAR) auto-focus image generation process is provided. Batches of raw radar return data are processed in order to form batch images which each have a valid region between invalid regions. The process determines an estimate of the first derivative of a phase error at an end of the valid region, determines a time-shift corresponding to that estimate and uses that information in determining a starting point for the next batch of raw radar return data.

Abstract: A buoyant device has a body and an elongate tail. The body carries a payload. The tail is moveable, e.g. by pivoting, between a closed and an open position. This movement changes the position of the center of mass of the device relative to the center of buoyancy. As a result the device can move through the water, with the tail in the closed position, with minimal drag. However, when the tail moves to the open position, the body pivots in the water so that the body, and hence the payload is supported in a stable manner.

Abstract: A mechanical linkage, for use on original equipment or for replacement of existing hydraulic ram based actuators, comprises a rotary to linear transmission. The transmission provides two co-rotatable capstans of different diameters, and two idler wheels spaced on a longitudinally slidable linkage. The capstans are linked to a first of the idler wheels by means of a pulley line wound from the first capstan, around the wheel, and then back to the second capstan. The first capstan is also linked by means of a pulley line to the second idler wheel, and the second capstan likewise to the second idler wheel by a third pulley line. The difference in diameters causes a differential winding of the various lengths of pulley line between the idler wheels and the capstans, which urges the linkage to slide relative to the capstans. Cooperation of the two capstan/idler wheel combinations compensates for possible backlash.

Abstract: An hermetically sealed integrated microwave circuit comprising a coplanar waveguide on a printed circuit board (PCB) electrically connected on one major surface to an integrated circuit, and thermally and electrically connected to a ball grid array (BGA) on its opposite major surface, in which the PCB has at least first and second printed layers, a microwave signal path extends from a ball of the BGA through a through-hole in both printed layers to the coplanar wave guide, and plural ground paths extend from balls of the BGA through first through-holes in the first printed layer of the PCB and through second through-holes of the second printed layer of the PCB, the first and second through-holes being non-coincident, to allow for an hermetic seal across the PCB whilst introducing a predetermined impedance in the PCB between the signal and ground paths.

Abstract: An assembly comprising a first printed circuit board, PCB, with a ball grid array, BGA, on its underside, a second PCB facing the first PCB and having at least one through-hole between its top and bottom surfaces, its top surface printed with a circuit pattern bonded to the BGA, a heat sink layer facing the bottom surface of the second PCB and having at least one thermally-conductive pin projecting normally into the through-hole or a respective one of the through-holes in the second PCB, and, for each pin, a thermally-conductive stud of the same cross-section as the pin, bonded to the BGA and disposed within the through-hole between the pin and the first PCB in thermal contact with the pin.

Abstract: A temperature activated switching circuit 100, comprising a temperature activated switch U1 for switching an output 102 at a threshold temperature, the temperature activated switch U1 having at least one power input VCC for receiving power; and power switching circuitry for connecting a power source to said power input VCC of the temperature activated switch U1, the power source being initially disconnected from the power input VCC, and the power switching circuitry being configured to connect said power source to the power input VCC based on a detected temperature, in order to power up the temperature activated switch U1 before said detected temperature reaches said threshold temperature.

Abstract: A method of analysing return signals of successive range cells in a scene using constant false alarm rate adaptive control comprising, for each successive range cell in turn is disclosed mathematically. The return signal is processed mathematically and averaged over a predetermined number of cells near that cell. A first variable factor and the return signal for that cell, to derive a first result. The first variable is adapted depending upon that first result. A second variable factor is derived in accordance with a predetermined relationship between the first and second factors are mathematically processed. The second factor is mathematically processed. The second averaged return signal and the return signal for the cell, to derive a second result. The second result is used as an indication of the presence of an object of interest in the scene.

Abstract: The invention relates to a method of analyzing signals from an array of sensors, the array including one or more pressure sensor and one or more pressure-gradient sensor. The method includes combining data received from one or more pressure sensors and data from one or more of the pressure-gradient sensors, in such a way as substantially to eliminate noise components from the product. The invention also relates to a sonar system and an array configuration for implementing the method, as well as a computer readable product, storage device storing the computer readable product and computer receivable signal for implementing the method.

Abstract: The invention relates to an imaging method and system for providing acoustic images of a surface and more particularly, but not exclusively, to acoustic imaging of a surface within a confined space. Also described are an acoustic probe and a transmit/receive sensor array configuration to implement the imaging method and system. The probe has an array of acoustic transmitters arranged in juxtaposed or spaced relationship around at least a portion of the circumferential surface of the probe, and an array of acoustic receivers also disposed around at least a portion of its circumferential surface. A beam-former is used for focussing and steering the acoustic beams from the acoustic transmitter array onto portions of the structure to be examined and for focussing and steering the receive beams onto said surface portions, said beam-former adapted to cause the acoustic transmit beams to be focussed in a plane orthogonal to the plane used to focus the receive beams.