Abstract: An optical system for a colour head up display, the optical system being for guiding image light from an image projection system to an exit pupil. First and second waveguides are utilised, each waveguide guiding a predetermined set of wavelengths.

Abstract: There is disclosed a tracer munition. There is provided a tracer munition for selective activation, the tracer munition comprising: an electronic tracer device, said tracer munition comprising at least one cavity capable of receiving said electronic tracer device wherein the electronic tracer device comprises an electrical power source and an electronic emitter, whereupon selective activation of the electronic tracer device, said electronic emitter emits radiation.

Abstract: An optical waveguide device for use in a head up display. The waveguide device provides pupil expansion in two dimensions. The waveguide device comprise a primary waveguide and a secondary waveguide, the secondary waveguide being positioned on a face of the primary waveguide. The secondary waveguide has a diffraction grating on a face opposite to the face which contacts the primary waveguide. The diffraction grating diffracts light into more than diffraction order. Rays diffracted into a non-zero order are trapped in the secondary waveguide by total internal reflection.

Abstract: According to the present invention, there is provided an electroacoustic transducer, comprising: a first electrode; a second electrode; a piezoelectric material at least partially sandwiched between the first electrode and the second electrode; and an optical aperture extending through the electroacoustic transducer, to allow for optical communication to take place through the electroacoustic transducer.

Abstract: A helmet mounting for optical combiner (50) for a HMD has a pivoted mounting arm (60) for the optical combiner to be movable between an operational position in a line of sight, and a retracted position displaced out of the line of sight. A translation mechanism (100) provides translation of the optical combiner along the line of sight. A driving lever (30) causes the displacement of the mounting arm between the line of sight and the retracted position, and with a second motion of the lever, causes the translation of the optical combiner. By having the same lever coupled to both the mounting arm and the translation mechanism, the relatively complex combination of displacement and translation movements of the optical combiner can be reduced to a simpler movement, easier for a user such as a pilot to use even when under stress in a busy and cramped cockpit environment.

Abstract: A system and method of positioning a set of vehicles (102) with respect to an object (104) and a set of targets (106). Embodiments can generate (302) an isovist using data obtained from at least one sensor associated with the object and use it to compute (304) an estimated position of each target with respect to the object. Embodiments can compute (306) a plurality of positions for each vehicle based on the estimated positions of the targets, with each position having an associated value representing a number of the targets at their estimated positions that are within a predetermined proximity of the vehicle at that position. Embodiments can select (308) a subset of the positions based on the associated values, and position (310) the set of vehicles based on the selected subset of the positions.

Abstract: Disclosed is a SONAR system operable to transmit a pair of pulses including an up-chirp signal and a down-chirp signal wherein the down-chirp signal is a time-reversed version of the up-chirp signal. Also disclosed is a related method of operation.

Abstract: An aircraft emergency control system comprises at least one sensor (104A, 104B, 104C) configured to output an electronic signal relating to detection of incapacitation of at least one aircraft crew member. A processor (108) is configured to receive and process the electronic signal to determine whether emergency action is to be taken. A control unit (114) is configured to communicate, in use, a control signal to an avionics system (116) of the aircraft (100) in relation to the emergency action if the processor determines that emergency action is to be taken.

Abstract: An adaptive camouflage device that includes at least one non-emissive layer which includes a guest-host liquid crystal (GHLC).

Abstract: A laser diode array (102) comprising a plurality of laser diodes (201-210) and a channel (212) proximate to each of the laser diodes (201-210), the channel (212) configured to receive and provide a passage for a flow of a fluid coolant; wherein the laser diodes (201-210) are configured to emit electromagnetic radiation having the same centre wavelength at different respective junction temperatures. A coolant supply system (104) coupled to the laser diode array (102) may cause coolant to flow through the channel (212). A flow rate of the coolant through the channel (212) may be controlled based on temperature measurements of the coolant prior to entering, within, and/or after exiting the laser diode array (102).

Abstract: According to an aspect of the invention, there is provided a communication system for communicating between a ranged weapon and a projectile for that ranged weapon, the system comprising: a transmitter associated with the ranged weapon, the transmitter being arranged to encode data to be transmitted to the projectile on an electromagnetic carrier wave, and to transmit that electromagnetic carrier wave to the projectile; a receiver associated with the projectile, the receiver being arranged to receive the electromagnetic carrier wave, and to decode data encoded in the electromagnetic carrier wave to retrieve that data, the data being usable in the activation of a fuse of the projectile.

Abstract: According to a first aspect of the present invention, there is provided a method for transmitting and/or receiving an optical signal through a fluid, the method comprising: using a pressure wave to cause a change in refractive index in the fluid, the change in refractive index causing a waveguide to be formed; and transmitting and/or receiving the optical signal through the waveguide.

Abstract: Diverse types of crew interfaces (400, 430, 450) are provided for outputting visible, audio and tactile information to a pilot for flight control. A unified estimation of the current aircraft state and of a current phase of flight are made (110), based on flight status information. Respective coordinated visible, audio and tactile presentations for the diverse types of crew interfaces are generated, (120) coordinated so that they provide mutually consistent indications of the unified estimation of the current aircraft state, according to the unified estimation of current flight phase. The respective coordinated presentations are output (130) by the diverse types of crew interfaces to the pilot. By coordinating crew interface outputs across sight, sound and touch senses, this can relieve the pilot of workload in interpreting unsynchronised or incoherent outputs from different types of interfaces.

Abstract: A waveguide structure for a head up display in which a reflective output coupling structure is formed of a separate, but connected, component to a main waveguide. In a method of manufacture for such a waveguide the output coupling structure may be formed by depositing a material on a main waveguide, impressing the reflective structure into that material, and curing the material.

Abstract: Fuse system for a projectile for a ranged weapon, the fuse system comprising: a plurality of magnetic field sensors, each sensor being arranged to provide a signal that changes in response to a relative change in position and/or orientation between the system and the Earth's magnetic field, and wherein each sensor has a different alignment in terms of magnetic field sensitivity, and a controller arranged to receive one or more signals from the plurality of magnetic field sensors, and to activate a fuse of the projectile depending on the received one or more signals.

Abstract: The present invention provides a vehicle comprising: a rotor and a stator; at least one planar control surface coupled to the rotor, wherein the rotor is configured to rotate relative to the stator such that, in use, the at least one planar control surface moves from a first position to a second position, and wherein in the first position the planar control surface is controllable to affect substantially only the pitch of the vehicle and in the second position the planar control surface is controllable to affect substantially both of the pitch and yaw of the vehicle, or substantially only the yaw, or in the first position the planar control surface is controllable to affect substantially only the yaw of the vehicle and in the second position the planar control surface is controllable to affect substantially both of the pitch and yaw of the vehicle, or substantially only the pitch of the vehicle. The present invention also provides a method of controlling a vehicle.

Abstract: A method is provided for operating an image generator, arranged to generate and to output signals for displaying image elements of a predefined set of image elements, each image element being defined by respective varying deflection signals. A colour change trigger is firstly defined comprising an additional image element defined by varying deflection signals different to varying deflection signals of an image element of the predefined set. Varying deflection signals of the defined colour change trigger are generated and output thereby to indicate a respective colour for use in displaying an image element of the predefined set. An image generator is also provided, configured to implement the method. A method is also provided for generating digital colour image data from signals output by such an image generator. A display system is also provided incorporating such an image generator together with a colour change trigger detector and scan converter.

Abstract: This invention relates to a combination of a gun having a rifled barrel and a round of enhanced performance ammunition, and to a projectile for use in the combination. The invention is especially, but not exclusively related to an improved form of projectile for small arms ammunition. There is provided a projectile with a nominal calibre, for use in a rifled barrel, the projectile comprising: a monolithic body, said monolithic body comprising a. an ogival portion forming the front of the monolithic body; said ogival portion at a point of intersection abuts with b. an elongate cylindrical core, said elongate cylindrical core comprising at least three bands located circumferentially thereon, said bands protruding radially outward therefrom; and said elongate cylindrical core abuts c.

Abstract: Disclosed is a method and apparatus for physically coupling together a first aircraft and a second aircraft, for example for the purpose of performing air-to-air refueling. The first aircraft is an aircraft in flight. The second aircraft is an aircraft in flight. The method comprises: sending, from a transmitter located on the first aircraft, an electromagnetic signal; receiving, by a receiver located on the second aircraft, the signal; and controlling, by one or more processors, using the signal received by the second aircraft, at least one of the first and second aircraft such that the first and second aircraft are in a predetermined configuration in which the first and second aircraft are physically coupled together, for example attached together.

Abstract: A method and apparatus are provided for determining the orientation of an object relative to fixed, moving or moveable platform likely to be exposed to buffeting or similar effects. The object may for example be a helmet worn by a pilot of an aircraft in which orientation of the helmet relative the aircraft while in flight may usefully be known, in particular when determining the position of space-stabilised symbols being displayed in an associated helmet-mounted digital display system. According to the method, not only may orientation of an object may be predicted at some time ahead of a time point of validity of source sensor data—a useful feature for digital display systems—but the functionality carrying out the prediction may be dynamically configured to according to a detected severity of buffeting upon the object and upon the tracker system sensors to reduce the effects of the buffeting upon the quality of data output by the tracker system.