Abstract: A sensor system for the measurement of a physical parameter, such as temperature or pressure comprises a first, fixed module (5), and a second module (20) positionable proximate to the first. The first module has a measurement coil (6) and a reference coil (7), where the measurement coil forms part of an electrical circuit that is subject to variation by the physical parameter, and the reference coil forms part of a circuit not subject to the physical parameter being measured. The second module has a pair of reading coils (22, 23), each arranged to couple to respective measurement and reference coils, where the reading coils are connectable to signal generation and measurement equipment, and the system is arranged to measure electrical characteristics of the measurement and reference coils via the coupling. It has particular utility in harsh environments such as in wells, where the first module may be fixed, and the second module may be lowered adjacent the first.

Abstract: Some embodiments are directed to a shaped charge liner including an apex end and a base end and defining a main liner axis that passes through the apex and base ends, the liner being rotationally symmetric about the main liner axis wherein the liner has discrete rotational symmetry about the main liner axis.

Abstract: A carrier for at least one shaped charge, the carrier being disposable in use within an oil, gas, water or steam well bore. The carrier comprises a housing at least partially formed from a composite material which is non-frangible in normal use. The composite material component of the housing is arranged substantially to contain debris created within the carrier as a result of firing of the at least one shaped charge. The housing may be entirely of composite material or may comprise in inner metallic housing and an outer overwrap of composite material.

Abstract: Some embodiments are directed to a radar imaging system that includes a radar transmitter configured to transmit radar at a target; an aperture including an array of physically independent airborne carriers, each of the carriers configured to receive radar echoes from the target; and a base station, which may be located at ground level, in communication with each of the airborne carriers to receive the radar echoes and determine an image of the target from the received radar echoes.

Abstract: A gearing assembly includes a rotary input member, a rotary output member, and a gearing arrangement between the input member and the output member selectively able to effect a driving engagement between the input member and the output member through at least a first torque connection having a first gear ratio. A second torque connection has a second gear ratio and a third torque connection having a third gear ratio. The gearing arrangement includes a first engagement member operable selectively to effect the first torque connection in a 1:1 ratio, a first planetary gear stage, and a second planetary gear stage. A second engagement member is operable selectively to effect the second torque connection, and a third engagement member operable selectively to effect the third torque connection, respectively, through one or more of the planetary gear stages.

Abstract: A wind turbine comprising a support structure and one or more turbine blades is disclosed, that incorporates means for reducing the radar cross section (RCS), wherein the support structure is notionally divided into an upper section in the shadow of the blade sweep area, and a lower section beneath the upper section, wherein the upper section is adapted to have the means for reducing the RCS, and the lower section does not have the said adaptation. The invention makes use of the realization that the blade masking the tower as it rotates (or the blade being masked by the tower if facing away from a radar), contributes significantly to interference to radar systems, and so localized application of e.g. RAM can give good RCS reduction at a lower cost than treating the whole structure.

Abstract: A drone detection radar can include a plurality of antenna systems, each antenna system being arranged to transmit a signal into an associated sector, and to receive signals reflected from targets in the sector, the sectors collectively forming a monitored volume, and wherein a sub-set of the antenna systems are active at any one time, with the active sub-set of antenna systems being arranged to monitor their respective volumes for a duration sufficient to measure Doppler signals associated with slow moving drones, with the radar being arranged to switch to a different sub-set of antenna systems after each duration, such that the whole volume is monitored within a predetermined period. Combining a staring array from an antenna system with a plurality of switched antenna system allows drones to be both detected and tracked, with appropriate selection of the predetermined period.

Abstract: The present invention discloses a detection device for discriminating between different materials, and a method for doing so. The device comprises an optical system having at least one optical focussing element and a receiving element. The receiving element is sensitive to electromagnetic radiation, typically in the millimeter wave band, and the optical system being arranged to focus incident energy from a scene onto the receiving element. The optical system comprises a prism element having a first surface and a second surface, the first surface being opposite the second surface. At least a portion of the first surface is positioned at an angle ? to the second surface. The angle ? varies between a minimum at a first position on the first surface and a maximum at a second position on the first surface.

Abstract: A drive member selection mechanism is described, including at least one drive member and at least two selector members, wherein the drive member includes a first and second face, and further includes, on each face, at least one projection, and the selector members include, on at least one face thereof, at least one complementary projection arranged to selectively engage with a projection of a drive member, the arrangement being such that the projection(s) of a selector member and the projection(s) of the first face of a drive member may be drivingly engaged in a first torque connection and the projection(s) of a selector member and the projection(s) of the second face of a drive member may be drivingly engaged in a second torque connection, wherein the second torque connection is opposed to the first torque connection.

Abstract: Methods and apparatus for determining a data signal. In an example, a method includes acquiring at least one image of a field of view at a first frame rate and identifying a sub-region of the field of view, wherein the sub-region contains an optical data signal. A plurality of images of the sub-region of the field of view may be acquired at a second frame rate, wherein the second frame rate is higher than the first frame rate, and a data signal encoded in the optical data signal may be determined from the plurality of images of the sub-region of the field of view.

Abstract: A shifting apparatus including a shaft extending along an axis, and at least one shifting feature, each of the at least one shifting feature including: a multi-part pin having first and second parts arranged to rotate relative to each other that extend through respective slots extending along the shaft; a drum arranged around the shaft and having channels extending along the length thereof wherein the first and second parts of the multi-part pin are respectively received for enabling torque transfer to the drum when the shaft is rotated, the drum also defining a track at least partially around its outer surface; a biasing mechanism for urging the drum towards a rest position along the length of the shaft; and a drive member selector member provided in operative relation to the track. The drive member selector member can be controlled to selectively engage a drive member.

Abstract: A method for the reception of a frequency hopped direct sequence spread spectrum signal includes acquiring the signal by splitting the received signal into a plurality of processing sub-channels, each corresponding to one or more hop frequencies; and within each sub-channel: i) subtracting any sub-carrier frequency from the received signal; ii) filtering the signal from (i) using a chip-matched filter; iii) selecting a sub-set of samples from the filtered signal; iv) correlating the sampled signal from step (iii) with a known reference signal to produce at least one correlator output. The output(s) from each sub-channel are provided to an input of a corresponding one or more common discrete time Fourier transforms (DTFT), and an output therefrom having a peak above a predetermined threshold is selected for further processing in the receiver. The method is a less expensive way of tracking the signal and can demodulate appropriately modulated signals.

Abstract: Some embodiments are directed to an electric motor that includes a stator including a plurality of circumferentially distributed drive elements for causing an electromagnetic driving force to be applied to a rotor of the electric motor in use. Each drive element includes a wire extending around a metal core to define a plurality of coils for magnetizing the metal core when current flows in the coils. At least one space exists between the metal core of each respective drive element and the coils around it. A cooling device is provided for transferring heat away from the drive elements. Each drive element further includes a heat conductor including a plurality of mutually electrically isolated metallic elements located in the or each respective space between the metal core thereof and the coils around it, for transferring heat from the coils to the cooling device.

Abstract: A system for compensating for phase noise, with particular application in lidar, includes a compensation interferometer that receives a signal from a source, and splits it into a first and second path, with a path length difference ?? between them. Typically the path length is significantly less than that of the return distance to a target. The output of the compensation interferometer, which consists of phase noise generated in time ?? is vectorially summed during a time similar to a signal flight time to a target, and the result used to reduce phase noise present on measurements of a target. It further includes means for selecting ?? such that competing noise elements are reduced or optimised.

Abstract: A system and method of using the same, wherein the system comprises: an optical surface having a diffractive image generating structure disposed thereon, the diffractive image generating structure itself comprising a layer of reflective material incorporating a plurality of grooved diffractive elements each having a periodic wave surface profile, the periodic wave surface profiles each having a groove alignment direction; a source of incident electromagnetic radiation arranged to illuminate the diffractive elements at an angle of incidence substantially normal to the plane of the surface of the diffractive elements; means for polarizing the radiation from the source, and means for polarizing radiation reflected from the diffractive elements; wherein the diffractive elements are configured such that, in use, polarization conversion of the incident radiation takes place, and wherein the diffractive elements are disposed in a two dimensional array of pixels to represent an image; and further wherein the means fo

Abstract: A method of tracking a plurality of signals from a single satellite comprises receiving a first signal transmitted by a satellite; receiving at least a second signal transmitted by the same satellite; applying a pre-filtering process to determine the cumulative in-phase and quadrature components of the first, second signals, and optionally any further signals; and applying a filtering process to the cumulated in-phase and quadrature components of the first and at least second signals to determine a range and range rate of the satellite; wherein the filtering process comprises applying a Kalman filter. The method results in a determination of the range and range rate from a single satellite with improved signal to noise ratio. The range and range rate so determined may be used, with data from other satellites, to produce a navigational position. The method may be used with each such satellite used in producing the navigational position.

Abstract: A celestial navigation system includes an optical device for receiving light from a celestial object, a spectrometer for measuring a spectrum of the light in sufficient detail to identify absorption and/or emission features, and a processor for processing the spectrum to match the spectrum, or a processed version thereof, against a set of reference spectra information in a database, a device for measuring the pointing direction of the optical device and a clock. The matching may be on a maximum likelihood basis. The system is thus able, on identification of a single star, and, using commonly available navigational almanacs, to calculate a geographical position. Celestial navigation takes place even when only one celestial object (that is also within the database) is visible, although improved accuracy may be obtained with multiple observations. Advantageously, the database includes stars of the K and/or M type, that have more characteristic spectral content.

Abstract: Some embodiments are directed to an apparatus for managing fluid flow in a vehicle, that includes an epicyclic gear set having first, and second inputs configured to receive rotational drive input from a torque output feature of a powertrain and a rotary actuator respectively. A pump driver is provided for driving a fluid pump, the pump driver being configured to receive rotational drive input from an output of the epicyclic gear set. A controller is configured to determine information corresponding to the rotational speed of the torque output feature using information generated by a rotational speed sensor and based on this control the rotary actuator, such that the pump driver is caused to rotate at substantially a pre-specified speed.

Abstract: An electronic hardware assembly including at least a first and second laminar component, wherein the first laminar components includes a die, the die including a substrate, a functional region and a first protective layer, and the second laminar component includes a second protective layer, wherein the first and second laminar components are arranged in a stack such that the functional region of the first laminar component is arranged within the assembly substantially between first and second protective layers.