Abstract: An optical seeker comprises a rotor (16) mounted on a bearing sleeve (42) to pivot about a pivot point (26) and to rotate about an axis of rotation (28). The rotor (16) carries an imaging system having a concave mirror (50) and a secondary mirror (52). The optical axis of concave mirror (50) and secondary mirror (52) form an angle with the axis of rotation (28). A sunshade (54) is connected to the rotor (16). The bearing sleeve (42) carries an optical element (56). An axle portion (58) is provided on the element (56), on which axle portion the secondary mirror (52) is mounted. The secondary mirror (52) is connected to the sunshade (54) through a stepping-up planetary gear having internal toothing (72), planet wheel (76) and external toothing (78). The planet wheel (76) is mounted on a carrier (74) connected with the axle portion (58).

Abstract: A detector (24) in an optical seeker is cooled by means of the Joule-Thomson effect by expansion of pressurized gas. The pressurized gas is generated by a compressor (10) and is guided through a molecular filter (18) to the cooling device (22). The molecular filter (18) adsorbs disturbing components of the pressurized gas. In order to regenerate the molecular filter (18) a gas flow is periodically guided in opposite direction from a storage vessel (30) through the molecular filter (18) to an outlet. In normal operation the molecular filter (18) is cooled by Peltier elements (38). During the regeneration it is heated.

Abstract: A nutating coupler arrangement is provided for driving an oscillating mirror movable about an axis of oscillation 12. A driving member 18, which rotates about a driving axis 24, is connected to the oscillating mirror through a coupler 28. The driving axis 24 is offset relative to the plane 34 perpendicular to the axis of oscillation 12 and extending through the pivotal point 30 of the coupler 28 at the oscillating mirror. The coupler 28 makes a nutating motion while the pivotal point 30 makes an oscillating motion.

Abstract: In a gravimeter the measuring mass is supported by springs which are arranged in regular array around the measuring mass and exert pressing forces on the measuring mass along lines of action extending at an angle to the horizontal. The state of equilibrium with a predetermined value of the acceleration due to gravity coincides with an extreme value of the force-versus-deviation characteristic of the spring system, whereby the measuring mass is held practically free from restoring forces by the spring system. A sensor detects deviations from a zero position and controls a restoring force generator. Two counter-acting sets of springs are provided. The springs are tension springs, the tensional force of which acts on the measuring mass as a pressing force through a lever transmission. A measuring range spring permits setting of measuring ranges. An advantageous construction therefor is described.