Abstract: A head-mounted or helmet-mounted display apparatus is provided. The apparatus includes an optical element which in use is disposed in front of the eyes of a user. The optical element has a waveguide portion. The apparatus further includes a light source of image-bearing light and two diffraction elements. Each diffraction element is configured for propagation of image-bearing light of the light source through the optical element. Each diffraction element is arranged to release the image bearing light from the optical element. The apparatus further includes a switching element for switching the image-bearing light repeatedly between the first diffraction element and the second diffraction element to provide a first visible image or a second visible image to the respective eye of a user.

Abstract: A point-to-point radio frequency (RF) communication system having one or more communication units coupled to respective television cameras and displays; and a further communication unit; wherein the units transmit video data to the further communication unit at frequencies greater than or equal to 50 GHz and at data rates greater than or equal to 1 gigabit/second; and the units receive video data transmitted by the further communication unit at frequencies greater than or equal to 50 GHz and at data rates 250 megabits/second. The units can each include an antenna with a waveguide diplexer and an RF transceiver circuit board having sufficient transmit/receive isolation for the transmitting and receiving to take place point-to-point at distances greater than or equal to 1 km.

Abstract: A method for compensating for the failure of an element in a phased array antenna assembly is provided. After failure of an element of the assembly, a composite pattern is generated from signals received by respective elements in the antenna assembly. This generated pattern is then compared to a standard composite pattern which was generated prior to the failure. Thus the necessity for remedial action can be assessed. If necessary, initial values for parameters associated with each element are assumed and an optimization is performed on the parameters. Consequently, a composite pattern can be generated which approximates the standard composite pattern. Once optimization has been achieved, the optimized parameters are applied to base settings for the assembly and operation of the phased array antenna assembly can be continued.

Abstract: There is disclosed a transducer apparatus for acoustic communications through a substrate at a predetermined centre frequency, the apparatus comprising: —an active piezoelectric element for generating an acoustic signal; an intermediate layer, having a surface for accommodating the piezoelectric element, and having a first array of protrusions on a surface opposite the surface for accommodating the piezoelectric element; and a second array of protrusions at the substrate, wherein the active piezoelectric element is mounted onto the intermediate layer, and the intermediate layer is secured in position relative to the substrate such that the first array of protrusions faces the second array of protrusions such that the acoustic signal may propagate through the first and second arrays. There are further disclosed a method of mounting such an apparatus and a plate suitable for use in the transducer apparatus.

Abstract: A process is disclosed for minimising jammer noise in receiver systems. The process comprises the use of a primary receiver (10) and a plurality of secondary receivers (11) for receiving signals. The process comprises the steps of:—separately correlating the signal received at each of the plurality of 5 secondary receivers with the signal received at the primary receiver;—determining the magnitude of the correlation between signals received at each of the plurality of secondary receivers with the signal received at the primary receiver; and,—minimising the signal received at the primary receiver using those signals received at the secondary receivers for which the magnitude of the correlation with the signal received at the primary receiver is above a threshold value.

Abstract: A method and device are provided for treating flammable materials, fuels for example, by irradiation of the materials with ultra-violet radiation. In one embodiment, the apparatus suited for connection to a fuel line includes a body with centrally-formed duct and UV light sources mounted outside of the duct at upper and lower sides. It is to be appreciated that the invention has utility for many different fuel system applications, for example in aircraft, boats and in other motive vehicles. Further, the device can be conveniently mounted, if desired, on different fuel platforms including on bowsers.

Abstract: A system and method for determining and displaying the suitability of water conditions in a zone for the launch or recovery of a smaller craft (10) from or to a host ship (12) is disclosed. The system and method detect one or more external environment parameters such as the height, direction and period of the swell, and one or more parameters relating to the ship operating conditions such as the heading, speed, pitch and roll angles, and processes these to determine the suitability of the conditions for launch or recovery.

Abstract: A display device to display a representation of a set of states, each one of the states being associated with a corresponding variable. Each of the states displayed is designated as being a most significant state for the corresponding variable. Input representing a probability estimate to be associated with a displayed state is entered and used to generate data for use in an expert system.

Abstract: A health monitoring system for complex networked apparatus includes a number of neuro-fuzzy inference apparatuses feeding inference results into a data fusion hierarchy. At each level in the hierarchy, fuzzy inference is applied to generate a desired output signal by processing selected input signals in accordance with a knowledge base defining fuzzy membership functions and fuzzy inference rules defined in advance. The knowledge base includes alternative definitions of membership functions and/or inference rules. The apparatus selects which definition to use according to environmental or other conditions, and predetermined selection criteria.

Abstract: The thrust vectoring apparatus comprises: a housing defining a primary outlet for emitting the primary jet; Coanda surfaces extending from opposing regions of said housing, and radially spaced from the primary outlet such that a step is defined between each Coanda surface and the primary outlet; ducts leading from a fluid source to secondary outlets; and flow control means operable to control the mass flow through the secondary outlets. When the jet engine operates to exhaust a primary jet through the primary outlet, low pressure regions are formed in the vicinity of the steps. Each secondary outlet is located adjacent one of the Coanda surfaces so as to emit a secondary flow into a low pressure region. On activation of the secondary flow by the flow control means, the primary jet is entrained by the Coanda surface opposing the Coanda surface adjacent said the secondary outlet from which the secondary flow has been emitted.

Abstract: Introduction or Withdrawal of an Elongate Member to or from a Free Body A method of moving an elongate member (12) along a predetermined axis (A-A) for the introduction or withdrawal thereof to or from a free body (11). The method includes providing an elongate guide surface (18) extending parallel to the predetermined axis, and also providing a plurality of support elements (26) which are slidable on the support surface in a direction parallel to the predetermined axis. The elongate member is supported on the support elements so that at least a major portion of the mass is supported. The elongate member and the support elements are moved along the predetermined axis. Apparatus for moving an elongate member in this manner is also provided.

Abstract: Methods and systems for producing data describing states of a plurality of targets using a processor in a system having at least one onboard sensor. The method includes obtaining data from at least one onboard sensor and performing a first data fusion process on the obtained onboard sensor data to produce onboard sensor fused data. Data is also obtained from at least one off-board sensor, and a second, different data fusion process is performed on the obtained off-board sensor data and the onboard sensor fused data to produce target state data.

Abstract: According to the invention there is provided an arrangement of protective material for dissipating the kinetic energy of a moving object including one or more layers of fibrous armour material encased within a sealed encasement, in which the sealed encasement is formed from a textile armour material which is impregnated with a polymeric substance.

Abstract: According to the invention there is provided a protective material for dissipating the kinetic energy of a moving object including a plurality of layers of fibrous armour material in which at least some adjacent layers of fibrous armour material are separated by one or more separator layers for reducing inter-layer friction.

Abstract: According to the invention there is provided a fibrous armour material for dissipating the kinetic energy of a moving object which is impregnated with a shear thickening fluid, in which the shear thickening fluid includes particles of a thickening agent suspended in a liquid, and the volume fraction of the thickening agent in the shear thickening fluid is selected so that the shear thickening fluid has a viscosity-shear stress characteristic substantially corresponding to curve B or lying between curve B and curve D as shown in FIG. 2.

Abstract: A data transfer method and system includes at least one switch device (102) configured, in use, to transfer data, directly or indirectly, between a plurality of computing devices (104). The at least one switch device is configured to provide a plurality of Virtual Local Area Networks (VLAN), each said VLAN being configured as a Virtual Channel (VC) by receiving data from a said computing device designated as a sole source of data over the VC. The VC data is transmitted from the sole source computing device as Ethernet frames (200) tagged with a VLAN tag (202). The VCs are routed through the at least one switch device according to a VLAN Id field of the VLAN tag of a said frame, with fixed and pre-determined routing of the frame being determined by configuration of the at least one switch device.

Abstract: A method and apparatus for identifying and analysing an aircraft landing site during flight is provided. The method includes the steps of using image capture means such as an infrared camera to capture in-flight images of the ground in the region of a possible landing site, using a database of computer modelled images of possible aircraft landing sites mapped to a global co-ordinate reference frame to compare the in-flight images with a modelled image of the possible landing site and optimising correspondence between the two images to obtain an in-flight image optimally mapped to the global co-ordinate reference frame. Thereafter, the landing site which corresponds to the optimally mapped in-flight image is analysed to ascertain the presence of any obstructions such as life forms, vehicles or newly erected buildings thereon.

Abstract: A process for reducing erroneous plots when detecting targets using High Frequency surfacewave radar (HFSWR) is provided. Detection of genuine targets is thereby enhanced. A first difference in range of an apparent target is determined, based on range data, associated with the apparent target. A second difference in range of the apparent target is determined, based on Doppler data, associated with the apparent target. The first and second range differences are compared to one another over time to assess a consistency therebetween.

Abstract: A helmet or head-mounted apparatus has a visor or other curved optical element in front of at least one eye of a wearer, which element also is used as a waveguide. Image-bearing light is injected into the waveguide via an input diffractive element, and propagates through the visor to an output diffractive element which releases the light. The optical powers of the curved waveguide and the input and output diffractive elements are selected so that the released light is delivered as an image to the users eye.

Abstract: Apparatus for providing antenna diversity for a radio transmitter/receiver (TR) comprising measuring means for measuring relative received signal strengths in a plurality of antennas in a selectable frequency range, means for selecting the selectable frequency range according to a transmission frequency of the TR, and connecting means for connecting the antenna having the greatest received signal strength to the TR. The apparatus may be combined with a plurality of antennas to form a diversity antenna system, for example for use with a personal radio. The antennas may then be disposed spaced apart on the user's body e.g. by being incorporated into a garment.