Abstract: There is disclosed a spectral imaging apparatus for processing electromagnetic (EM) radiation, the EM radiation originating from a target scene and comprising a wide range of frequencies, the system comprising: A dispersive element for receiving EM radiation from the target scene and promoting differing amounts of dispersion depending on the frequency of the EM radiation, A deformable lens arranged to receive EM radiation from the dispersive element, An imaging sensor for detecting EM radiation across the wide range of frequencies, and arranged to receive EM radiation from the deformable lens, Wherein the deformable lens is operable to adopt any one of a plurality of focal conditions, each focal condition tending to focus a different range of the EM radiation at the imaging sensor, each focal condition thereby defining a component band for the EM radiation.

Abstract: A profiling approach for determining a path for an aircraft, using a method comprising the steps of determining at least two waypoints betweena starting position and a desired terminal position for the aircraft, determining a path for the aircraft between the starting position and the terminal position, by performing a linear approximation of the heights of the waypoints such that the average height change between waypoints is minimised, and constrained by a maximum climb angle of said aircraft, and performing a linear approximation of arrival times for each of the waypoints and aircraft speeds between the waypoints, constrained by permissible velocity of said aircraft on the slope between the waypoints. In this way, the non-linear relationship between climb rate and speed is approximated with linear equations, because determination of the path between each set of two waypoints is broken into two linear problems.

Abstract: An inceptor apparatus (10) for controlling a vehicle, in particular an aircraft comprises a control stick (15) for operation by a user and a user feedback generator (28) coupled to the control stick and configured to receive signals from a vehicle condition indicator (40) remote from the inceptor apparatus. The apparatus also has a first vehicle condition sensor (54,56) dedicated to the operation of the inceptor apparatus. In a first mode of operation, the user feedback generator (28) is operable to generate tactile feedback to the user via the control stick in dependence upon signals received from the vehicle condition indicator (40). In a second mode of operation, in the event that no signal is received from the vehicle condition indicator (40), the user feedback generator (28) is operable to generate tactile feedback to the user via the control stick in dependence upon signals received from the first vehicle condition sensor (54,56).

Abstract: A vibration damping counterbalance unit for an inceptor apparatus having a wall defining a cavity; and a plurality of vibration damping masses housed within the cavity.

Abstract: A method and apparatus are provided for classifying range profiles, generated for example by a radar, lidar or sonar. In the method, each in a set of objects of interest is modeled with a probabilistic model. The probabilistic model represents the probabilities of occurrence of different possible sequences of distances between selected features of the object, in different orientations, that are likely to result in peaks of backscatter in a range profile of the object. The probabilistic model is derived from a first probabilistic representation of each selected feature, generated to represent the uncertainty in locating the feature and the uncertainty in observing the feature in a range profile. Classification is achieved by calculating, for each probabilistic model, the probability that the model would generate a given sequence of distances between observed backscatter events in a given range profile.

Abstract: An image combiner for a viewing device, such as a night vision device, is disclosed for combining a first image, such as generated symbology, with a second image, such as a view of an outside scene in reduced lighting conditions. A waveguide is provided for capturing the first image from a first viewing direction, and for directing the first image in a second viewing direction, the second viewing direction being substantially coincident with a viewing direction of the second image, such that the first image can combine with the second image. At least a portion of the waveguide is arranged to substantially transmit the second image, such that the second image can pass substantially through the waveguide.

Abstract: An electronic fuze system comprising a fuze setter (110) and electronic fuze (112), wherein signals are transmitted between the fuze setter (110) and the electronic fuze (112) by a radio-frequency electromagnetic coupling link which facilitates data transmission via a wireless communication standard between a first induction-loop antenna (116) and a second induction-loop antenna (118) driven by the electronic fuze.

Abstract: A method and apparatus for processing measurements of an acoustic wave, the acoustic wave being within a member (12) made of a composite material and caused by an impact to the member (12), the method comprising: analyzing the measurements to detect an initial acoustic wave feature; analyzing the measurements to detect the presence of further acoustic wave features, the further features occurring after the initial feature; if there are no further acoustic wave features, determining that the impact to the member (12) has not changed the structure of the member (12); if there are further features, determining a value of a function of the further acoustic wave features; if the determined value satisfies certain criteria, determining that the impact has changed the structure of the member (12); and if the determined value does not satisfy the criteria, determining that the impact has not changed the structure of the member (12).

Abstract: A method is disclosed of applying a non-secure warning tone to a packetized voice signal which includes receiving a voice signal containing a sequence of voice samples; providing a non-secure warning tone signal containing a plurality of tone samples; and modifying the voice signal by selectively including tone samples in the sequence of voice samples.

Abstract: An air vehicle powered by a gas turbine engine, particularly, but not exclusively, an air vehicle having a blended wing body includes a gas turbine engine disposed in the body of the vehicle including an inlet face. An inlet channel having a convoluted geometry is configured such that air flow incident on the inlet face during operation is disordered. A structural element associated with the inlet channel and locate upstream of the inlet face is provided. The element is configured to modulate air flow, at least partially, to improve flow ordering in the incident air.

Abstract: The present invention relates to air cooling of equipment and is more particularly, although not exclusively, concerned with the use of air at ambient temperature to effect cooling of electronic equipment. Accordingly, there is provided ambient air cooling apparatus comprising: a chamber in which items to be cooled are located; an air inlet; at least one air outlet; at least one fan for drawing air from said air inlet, through said chamber and over the items to be cooled, and to said at least one air outlet; a heater for heating air within said cooling apparatus; and a controller for controlling the operation of said heater and said at least one fan.

Abstract: A cavity system that tends to increase the thickness (28) of the shear layer (22), comprising: a cavity (2) and a plurality of rods (4), for example between two and six rods; the rods (4) are positioned in the proximity of a leading edge (14) of the cavity (2) and extending across at least a part of a width of the cavity (2) in a perpendicular or oblique angle to the actual or intended flow direction (6). One or more of the rods (4) may be positioned further along the flow direction (6) compared to one or more of the other rods (4), for example to provide a zig-zag pattern of rod positions. One or more flow alteration elements (34, 38), for example channels (34) passing through the rods (4) and/or protrusions (38) extending from the rods (4), may be provided on one or more of the rods (4).

Abstract: A method for manufacturing a waveguide for a display apparatus comprising providing a planar optical waveguide part (20), depositing upon the optical waveguide part a fluid material (11) curable to form an optically transparent solid, impressing (30) upon the fluid material an impression defining an input diffraction grating region, an intermediate diffraction grating region and an output diffraction grating region wherein the fluid material of the intermediate diffraction grating region is continuous with the fluid material of at least the input diffraction grating region, curing (45) the impressed fluid material to solidify said impression. The physical location of the input diffraction grating is located wholly within the geographical area of the intermediate grating, and the grating vectors of the input diffraction grating and the intermediate diffraction grating are oriented in different respective directions.

Abstract: Apparatus for and method of processing radio frequency signals, the method including: obtaining a signal indicative of a first frequency (e.g. by obtaining a sample of a transmitted signal), the first frequency being a frequency of the transmitted signal; and using the signal indicative of a first frequency, establishing a second frequency depending on the first frequency, the second frequency being a frequency to which to tune a filter for filtering a received signal. An antenna for receiving and/or transmitting a signal may be a co-site antenna with respect to at least one other antenna.

Abstract: A cavity system that tends to increase the thickness (28) of the shear layer (22), comprising: a cavity (2) and a plate (104); the plate (104) comprising a plurality of holes (4) through it, wherein the proportion of the area of the plate (104) taken up by the holes is ?60%, for example ?75% or ?90%; the plate (104) being positioned in the proximity of a leading edge (14) of the cavity (2); the surface of the plate (104) at a perpendicular or oblique angle to the actual or intended flow direction (6). The plate (104) may be positioned at an oblique angle to the flow direction (6). One or more flow alteration elements, for example elongate members (34) positioned across the holes and/or members (38) positioned directly behind or in front of the holes (4).

Abstract: An apparatus and method are provided for capturing dynamically selectable data streams from a communications network substantially at network line rates and for routing packets in selected data streams to one or more pre-assigned outputs by means of multiple selectable data processing queues.

Abstract: A method and apparatus are provided for detecting a fault condition in a network, making use of standard parameter data generated by a network termination device of a user of the network, the method comprising, in a training phase, the remote retrieval of selected parameters from a predetermined set of users' network termination devices in order to generate one or more representative models of expected operational status using the retrieved parameters and, in a monitoring phase, determining a measure of operational status for the set of users at some future time and comparing that with a corresponding expected model measure. Parameter retrieval takes place over substantially the same path through the network as used to supply services to a respective network termination device so that the models are generated in respect of communications over those elements of network infrastructure likely to affect operational status of the respective set of users in the event of a fault condition.

Abstract: A waveguide for a display apparatus comprising a planar optical waveguide part (20) for guiding light to be displayed, an input diffraction grating (21) to diffract received light (7) along the optical waveguide part for guiding thereby, an intermediate diffraction grating (22) to receive diffracted light from the input diffraction grating and to expand the received light in a first dimension by diffraction (8), and an output diffraction grating (23) to receive the expanded light and to output the received expanded light (10) from the optical waveguide part by diffraction for display. The input diffraction grating is positioned so as to be located wholly within the geographical area of the intermediate grating, and the grating vectors of the input diffraction grating and the intermediate diffraction grating are oriented in different respective directions.

Abstract: A method and apparatus for compensating for hysteresis in a system, the method comprising: determining a required input to the system from an output of the system using the Preisach model with the input of the Preisach model corresponding to the output of the system, and with the output of the Preisach model corresponding to the input of the system. The system may be an adaptive optics system. The input x may be an input voltage of an actuator that deforms a mirror, and the output y may be a value of a displacement of a mirror.

Abstract: A method and apparatus are provided for monitoring data communications performance over at least a portion of a network having a plurality of network users each having, linked to the network, a network termination device for accessing services over the network. In a training phase, remote connections are established to the network termination device of each in a predetermined set of network users served by a predetermined portion of the network to retrieve parameter data generated by the device, the parameter data comprising values for a predetermined set of parameters indicative of data communications performance over that portion of the network. Principal component analysis is applied to the retrieved data to determine the principal component directions of variation.