Abstract: An electrode arrangement for an electrical impedance tomography system comprises a plurality of electrodes in an array mounted in a support medium for supporting the electrodes adjacent a surface of a volume the electrical conductivity distribution of which is to be measured, for example the thorax or another body part, a pipeline, the ground, and so on. The electrodes are disposed in two groups, the arrangement being such that, in use, one group will be closer to the surface than the other group, In operation, applying a known current to them. For each stimulated pair, a resulting potential difference will be recorded at the pair of the remaining electrodes which, if stimulated, would produce an electric field with vectors of the electric field produced by the stimulated pair of electrodes.

Abstract: A machine gun unit comprises a machine gun mounted to a support by a mounting permitting pivoting movement of the machine gun relative to the support in azimuth and/or elevation. Angle encoders provide position signals representing angular displacement of the machine gun relative to the support. An aiming system comprises a sensor, for example a CCD sensor, which provides a video signal representing a field of view for the aiming system, a display device for displaying the field of view, a manual input interface, a graphics artifact generator, and a digital signal processor (DSP). The DSP monitors the outputs of the angle encoders and controls the graphics artifact generator to combine the output of the graphics artifact generator with the output of the CCD sensor for display by the display device. Various graphics artifacts can be provided. Masks may be provided for delimiting field of fire. A cursor may be repositioned to reflect superelevation requirements.

Abstract: A machine gun unit comprises a machine gun mounted to a support by a mounting permitting pivoting movement of the machine gun relative to the support in azimuth and/or elevation. Angle encoders provide position signals representing angular displacement of the machine gun relative to the support. An aiming system comprises a sensor, for example a CCD sensor, which provides a video signal representing a field of view for the aiming system, a display device for displaying the field of view, a manual input interface, a graphics artifact generator, and a digital signal processor (DSP). The DSP monitors the outputs of the angle encoders and controls the graphics artifact generator to combine the output of the graphics artifact generator with the output of the CCD sensor for display by the display device. Various graphics artifacts can be provided. Masks may be provided for delimiting field of fire. A cursor may be repositioned to reflect superelevation requirements.

Abstract: In apparatus, such as a weapon sight, the speed of an object moving relative to a scene is determined by processing a plurality of successive frames of data, each obtained by scanning the scene, and detecting motion of the object relative to the background/foreground features of the scene. Each frame is compared with a reference comprising a different one of the frames and corresponding background features registered. Once the frames are registered, light intensity values of corresponding elements of the frames are subtracted. The registered background features, being stationary, cancel leaving the object features. Displacement of the object features over a predetermined number of frames is used to calculate the crossing speed of the object relative to the background features.