Abstract: Process and system for the location of emitters in the radar frequency range on the basis of cross position-finding by at least two flying platforms with, in each case, at least one passive HF sensor for ascertaining the geometrical and electronic properties of the emitter beams, whereby the flying platforms mutually exchange data for describing the geometrical and electronic properties of the emitter beams, and whereby from the plurality of the position-finding beams' possible intersection points, which arise from the emitter surveying operation, use is made, in order to determine the emitter position, of those intersection points at which the electronic properties of the intersecting emitter beams are identical.

Abstract: Process and system for the location of emitters in the radar frequency range on the basis of cross position-finding by at least two flying platforms with, in each case, at least one passive HF sensor for ascertaining the geometrical and electronic properties of the emitter beams, whereby the flying platforms mutually exchange data for describing the geometrical and electronic properties of the emitter beams, and whereby from the plurality of the position-finding beams' possible intersection points, which arise from the emitter surveying operation, use is made, in order to determine the emitter position, of those intersection points at which the electronic properties of the intersecting emitter beams are identical.

Abstract: A semiconductor device for converting light into electric energy comprises at least one layer of amorphous silicon with a surface thereof which is intended to be exposed to light covered by a cover layer of polycrystalline silicon. The use of the polycrystalline silicon increases the current yield in the blue light range of the solar spectrum. A method of producing such a semiconductor device is also disclosed.

Abstract: A semiconductor solar cell for the conversion of light to electric energy comprises at least one layer of amorphous silicon, a cover layer of poly-crystalline silicon and an anti-reflection layer of semiconducting transparent oxide of a refractive index of less than 2.8. The cover layer of poly-crystalline silicon has an optical density ##EQU1## or it may be ##EQU2## The cover layer is arranged between the anti-friction layer and the layer of amorphous silicon.

Abstract: A method and device for manufacturing semiconductor elements of amorphous licon which convert light into electrical energy comprising, supplying a silicon compound to a vessel, passing an electric field through the vessel sufficient to produce a glow discharge having free electrons in the vessel to precipitate amorphous silicon from the silicon compound onto a substrate in the vessel, and providing a magnetic field in the vessel which is directed substantially transversely to the electric field and is of a magnitude sufficient to conduct the free electrons along closed paths over the surface of the substrate.

Abstract: A reflector of an optical system has its position controlled by piezoelecc devices operating at three points of the reflector disposed at the apices of an equilateral triangle. These are driven by summing amplifiers each of which has an input to which a signal for producing displacement of the reflector without change of tilt is provided and one or more inputs connected to the output of a matrix circuit responsive to signals for producing tilt of the reflector about two mutually perpendicular axes both perpendicular to the direction of displacement produced by the previously mentioned inputs.