An aircraft threat monitoring system has several sensors responsive to a potential threat external to the aircraft such as a radar warning receiver, a radar sensor, a missile approach warning receiver, a forward-looking infrared detector and an electro-optic sensor. Each sensor has a respective inference processor the outputs of which are supplied to a groundspace map manager and an airspace map manager. The map managers collate the processor outputs to derive a threat output signal which is sup...

In a telephone system having an automatic response function wherein a predetermined answer message is automatically sent to a calling originator when a speaking path to the calling originator is established in response to a call signal originated by calling from the calling originator, there are provided a DTMF signal decoder for decoding a DTMF signal sent from the calling originator as a result of key operation at the calling originator after the speaking path has been established, and a memor...

An imaging system (10) comprises an imaging data-collection station (11) having a camera (15) with a field of view (16) mounted on platform (13) rotatable about azimuthal axis (14). Collected image data is delivered on line (20) to a monitoring station (12) together with data on line (19) representative of the angular position of platform (13) which is sensed by sensor (18). The monitoring station (12) incorporates at least one channel each channel having a display device (25) having a known dis...

A guidance method which enables a moving body to be guided to a predetermined location by allowing the body to view its surroundings and to compare the viewed scene with a reference pattern stored on the body. A number of individual reference patterns are stored, and each reference pattern corresponds to an area of the surroundings which is very much smaller than the field of view and thus the body identifies its position by correlating its field of view with one of the reference patterns. To en...

A roofing system includes a filler member (12) engaging the under sides of the tiles (3) at the eaves of the roof. The filler member (12) is carried by a strip (13) which is pivotable on a spacer member (4), having ventilation apertures (6), the spacer member (4) being secured to the top of an underlying fascia board (1). The strip (13), which is also effective to support the roofing felt (14), extends inwardly from the spacer member (4) and engages the rafters (2), whereby to locate the filler ...

A radio system employs a method of controlling the transmitted power of a radio signal such that a minimum power level for efficient reception is maintained. Data is simultaneously transmitted between two radio stations using an error correction code. Each block of the code is accompanied by a power bit. The transmitted power bit is set high or low in dependence upon whether the number of errors in a sample of received blocks, as determined by processing of the received code, is equal to, above ...

In order to remove broken threads and debris from textile drawing equipment having a drawing cylinder, a suction pipe connected to an air pressure sink is provided with a triangular suction opening at the drawing cylinder for removing the broken threads and debris. For substantially improved performance at essentially the same air throughput, the suction pipe, in continuation of its triangular suction opening, is provided with a triangular cross-section being congruent with the triangular suctio...

Improvements in an oscillating sprinkler having an improved discharge of fluid wherein the fluid being discharged enters two side by side curved chambers and is split into two separate streams. The spring controlling the oscillation of the sprinkler is centered on the impact arm of the sprinkler by a spring retainer and a boss on the arm itself so as to provide a smooth transition for the water and disperse it evenly with less operating pressure. The arm may have a removable reactor spoon portio...

An engine system for a road vehicle includes an engine having an exhaust manifold which is coupled to an exhaust gas treatment device. A device is provided to deliver vaporized fuel or to burn fuel in the air inlet manifold to increase the level of noxious gas in the engine exhaust. In this case the treatment device is of the catalytic variety and the increase in the noxious gas content causes an increase in the temperature of the active mass of the treatment device resulting in self cleaning. F...

A drive circuit applies an oscillating signal to the drive coil of the fluxgate thereby generating output pulses from the detection coils of the fluxgate, which pulses have an area proportional to the magnetic flux through that coil. The output pulses are integrated sequentially by an integrator. The output may be used directly to obtain the orientation of the fluxgate, and hence of a vessel in which the fluxgate is mounted but it is preferable on the grounds of accuracy and speed of response to...