Abstract: An apparatus for generating one or more radar return signals representative of one or more remote objects useable in ground based, shipboard and airborne radar systems for testing the radar and its user. The apparatus may generate one or more return signal scenarios which may if required interact with the real or preprogrammed movement of the craft in which the radar is fitted. To ensure accurate and repeatable radar return signal generator apparatus operation, the radar's own built-in test signal output is used by the apparatus to calibrate the radio frequency portion of the apparatus, which adapts a remote object return signal scenario into the crafts radar device. To further improve the accuracy of the return signal, a digital first-in-first-out (FIFO) delay means is used to accurately allow the delayed reuse of the radar's own transmission signal.

Abstract: A method of co-ordinate registration for Over-the-Horizon Radar comprising he steps of generating a geographic auto correlation function to determine one or more geographic beacons in a coverage area of the Over-the-Horizon Radar, the auto correlation function being in polar co-ordinates, comparing the return radar signal with the geographical map of the coverage area in the general region of the one or more geographic beacons and finding the best fit of the geographic map with return radar signal to enable registration of co-ordinates of the return radar signal. The auto correlation function indicates the amount of correlation between a neighbourhood and a slight displacement from that neighbourhood. A geographic beacon is an area in which there is a substantial difference between the neighbourhood and its surroundings thereby producing a low auto correlation function.

Abstract: A method of obtaining oceanographic and meteorological data from high frequency radar spectral information comprising the steps of transmitting a plurality of signals to a remote location, recording signals backscattered from the said location, generating a family of Doppler cluter spectra from the recorded backscattered signals and analysing the Doppler clutter spectra in terms of a model or models to detect the presence of rainfall. The model or models identify the presence of rainfall by detecting a reduced amplitude in some parts of the Doppler spectrum, especially in the "wings" of the spectrum by which is meant the regions where the magnitude of the Doppler shift is greatest. The method may also be used by detecting opportunity signals scattered from a remote location.

Abstract: A marine dye composition comprising a water soluble or dispersible dye, particles of a density controlling material having a bulk density and being present in an amount so as to cause said composition to have a relative density of about 1 and to be capable of floating at the surface of a body of water and a water soluble or dispersible binding agent for binding the dye and particles of density controlling material together.

Abstract: A method of testing oil for unstable reactive compounds include reacting unstable compound from an oil sample with an acid catalyst to form a reaction product, the color of which is then related to the presence and/or amount of reactive compound in the oil. Kits combining the necessary materials and reagents for performing the test method are also provided.

Abstract: A thermal infrared detector comprising a dielectric pellicle suspended over a cavity in a substrate, the pellicle supporting a detector element comprising a heat sensitive semiconductor layer between a pair of thin fim metallic contracts, these being deposited on the pellicle, the cavity being formed by etching and removal of the substrate material through holes or slots in the surface of the substrate.

Abstract: Cheese containing substantially all the casein and whey protein present in milk is prepared by concentrating milk, increasing ionic strength of the concentrated milk, fermenting the concentrate with a lactic acid-producing bacteria and evaporating water from the fermented concentrate. By increasing the ionic strength, coagulation is prevented during fermentation to produce a liquid fermented concentrate that can be efficiently evaporated. Preferably, milk is concentrated by ultrafiltration and diafiltration to produce a retentate having a concentration ratio of about 3:1 to 6:1, ionic strength of the retentate is increased by adding sodium chloride in an amount of about 0.5 to 1.5%, the retentate is fermented to a pH of about 4.9 to 5.5 and the fermented retentate is continuously evaporated at below atmospheric pressure.

Abstract: A method of assessing a link for a digital communication system and providing a value for a channel or link state parameter, particularly bit error rate, and apparatus for the same, in which an estimate of the probability density function for the channel or link is obtained by categorising decision variables into threshold categories, and comparing the estimated probability density function with stored known probability density functions with each stored probability density function the value of the channel parameter being monitored is stored. The value of the channel parameter being monitored is determined by selecting the value associated with the stored probability density function closest resembling the estimated probality density.

Abstract: A method of reducing tracking errors in an area comprised of touching surveillance regions which involves; transmitting a plurality of signals into a region, receiving signals scattered from the region and analyzing the received signals using a processing means, to produce target measurements; dividing each region into a number of zones comprising an edge zone at each edge of said region and one or more center zones; associating target measurements with appropriate zones; apportioning said measurements into data blocks on a storage means such that each pair of adjoining edge zones form a single data block and each central zone forms a data block; updating target tracks in each data block using said target measurements; allocating target tracks from each data block to the correct region; and displaying the tracks on a visual display means. A separate list of tracks for those targets contained in the edge track zone of touching regions is maintained.

Abstract: A cochlear prosthetic package having a cup-shaped titanium case with a ceramic plate; a plurality of hermetically-sealed feedthroughs are formed in the plate by sintering the plate with hollow metallic tubes located in plate holes and then sealing at least one end of each tube. An electrode cable connector is provided which allows removal and replacement of a case even in the presence of body fluids. A telemetry coil is contained in a metallic tube which extends out of the case; the coil-containing tube has its two ends hermetically-sealed to the case by ceramic insulating bushings.

Abstract: Distillate fuel is stabilized against degradation during storage by inserting into storage tanks solid materials containing polar sites to enable polar condensation of the fuel constituents active in degradation. Polyether or polyester polyurethane open cell foams are the prime solid stabilizers proposed.

Abstract: A modified Allison T56 turbo prop engine having reduced smoke emission and improved fuel economy. The air inlet apertures in primary combustion zone of the combustion liners are enlarged and shaped to allow more air to enter the combustion zone.

Abstract: A cochlear prosthetic package having a cup-shaped titanium case with a ceramic plate; a plurality of hermetically-sealed feedthroughs are formed in the plate by sintering the plate with hollow metallic tubes located in plate holes and then sealing at least one end of each tube. An electrode cable connector is provided which allows removal and replacement of a case even in the presence of body fluids. A telemetry coil is contained in a metallic tube which extends out of the case; the coil-containing tube has its two ends hermetically-sealed to the case by ceramic insulating bushings.

Abstract: An interferometric fibre optic network includes a downlead optical fibre (12) and a pair of uplead optical fibres (14, 16). Sites for a plurality of interferometric sensor pairs (25) are arranged whereby each pair (25) is optically connected in use of the network to the downlead and uplead fibers (12, 14, 16) via a 3.times.3 fibre optic coupler (30) and respective further fibre optic couplers (32) on the uplead fibres (14, 16). The uplead fibres (14, 16) are multimode optical fibres, and each of the 3.times.3 couplers (30) is optically connected to the respective further couplers (32) by a single mode optical fibre (34). The further couplers (32) are asymmetric couplers having high tap-on coupling from the single mode optical fibre (34) to the respective uplead fibre (14, 16) but low tap-off coupling from the uplead fibre (14, 16).

Abstract: This invention relates to a target which is towed by an aircraft to simulate the approach of an aircraft, missile or similar threat to a Defence System, to provide realistic practice for the Defence System. In accordance with this invention there is provided a target that is connected by a cable to a tow aircraft and towed by the aircraft toward a Defence System at a low approach altitude. The target has flight surfaces that, in combination with the mass of the target, cause the target to be towed at a substantially lower altitude than the tow aircraft. This allows direct ground or sea skimming approach by the target as the tow aircraft overflys the Defence System. The target is provided with a cable release means that releases the target at a predetermined safety range, whereupon the cable rises to a free streaming height and clears the Defence System.

Abstract: An optical sensor includes elongate light transmission means such as an optical fibre (13). A lens (16) of at least nearly half-pitch length is positioned with one of its focal planes substantially at a mouth (13a) of the optical fibre to receive and focus a diverging cone of light emergent therefrom. A reflector (20) is disposed substantially at another focal plane of the lens to reflect the focused light back to the mouth of the fibre. Detection means (14) in the path of the light between the mouth and the reflector is arranged to influence the light in response to an external condition in a manner whereby the reflected light received back at the fibre mouth may be monitored to detect the influence and thereby the condition. An optical fibre network has an incident fibre (40) and a detection fibre (42) coupled to plural optical components (60) via respective optical fibres (62) associated with the components and one or more optical fibre couplers (64, 68, 69).

Abstract: A cochlear prosthetic package having a cup-shaped titanium case with a ceramic plate; a plurality of hermetically-sealed feedthroughs are formed in the plate by sintering the plate with hollow metallic tubes located in plate holes and then sealing at least one end of each tube. An electrode cable connector is provided which allows removal and replacement of a case even in the presence of body fluids. A telemetry coil is contained in a metallic tube which extends out of the case; the coil-containing tube has its two ends hermetically-sealed to the case by ceramic insulating bushings.

Abstract: A flare (1) for submarine use. The flare (1) is caused to be deployed from a submarine location where it will rise to the surface of the water because of its buoyant casing. A hydrostatic valve means (147) is provided within the casing and it opens when the flare is at or near the surface of the water to render said flare ready to project a flare composition (5) into the air. The hydrostatic valve means (147) is held inoperative by a latch mechanism (51) which is tripped as the flare is deployed from a firing tube at the submarine location. The flare composition (5) cannot be projected into the air until the flare (1) is within a range of vertical attitude determined by inclination means (13). The flare composition (5) cannot be projected into the air until the nose is above water. The flare (1) thus has a sensor (23) at its forward nose to determine that the nose is above the water.

Abstract: A means of reflecting and emitting electromagnetic energy in an appropriate wavelength band comprising an arrangement (10) of surfaces (11) which are reflective to energy in that wavelength band and energy emitters (12) having an emission of energy of such intensity that the combined reflection and emission of said surfaces match energy of a background in that wavelength band thereby camouflaging the surfaces. The said emitters (12) comprise strips of material which, upon energizing with an electric current, become heated and radiate energy. The means further comprises at least one radiometer (17) in association with a comparison means to provide an electrical signal which is a function of the difference between the combined reflection and emission and of the background, the electrical signal controlling the energization of the energy emitters (12).

Abstract: An apparatus and method of measuring the stress and strain characteristics of adhesives under uniform shear conditions. An Iosipescu sample (10) is used, in which at the shear line, the sample is joined by the adhesive to be tested. Pure shear is applied to the sample at the bond line and the distortion of the adhesive bond is measured. The apparatus (20) is attached to the specimen (10) by clamp means (30). The apparatus (20) comprises a fork means (22) and means to transmit the displacement (21) of the two parts of specimen (10) to the fork means (22) and means to measure the displacement, for example strain gauges attached to a Wheatstone bridge circuit. The specimen (10) with apparatus (20) attached is placed into a tensile testing machine especially adapted to receive the sample and apply shear to the adhesive bond line.