Abstract: A method for detecting precipitation using a radar sensor system for motor vehicles designed for locating objects in the surroundings of the vehicle, in which method a locating signal that is a measure of the received power density as a function of the distance is integrated across a specific distance range lying below a limit distance for detecting precipitation. The locating signal is subjected to a filtering procedure before being integrated, the filtering procedure suppressing the peaks caused by located objects so that the filtered signal forms a measure of the noise level as a function of the distance.

Abstract: A method for the detection of sensitivity losses of an FMCW radar locating device due to diffuse sources of loss, in which the radar locating device emits a transmit signal whose frequency is periodically modulated in successive modulation ramps, and at least one power characteristic of at least one frequency portion of a signal received by the radar locating device is evaluated, wherein the power of the transmit signal is varied cyclically, in each case after the completion of a modulation ramp, and the sensitivity losses are determined on the basis of differences in the power characteristics of signals received during successive modulation ramps having identical modulation.

Abstract: To determine the visual range of, in particular, a driver in a motor vehicle, a contrast ((c(x1), c(x2)) is measured from at least two measuring positions (x1, x2) of a measuring device situated at different distances from the object, and the ratio of the measured contrast values is converted to a visual range (?), using the difference of the distances of the measuring positions from the object.

Abstract: An ellipsometer measurement apparatus for determining the thickness of a film applied on a substrate, is described. The apparatus includes a light source emitting an incoming beam, a transmitting optical system conveying the polarized incoming beam to an incidence point on the substrate, and a receiving optical system that has an analyzer and conveys the reflected beam formed at the incidence point to a photodetector device, the polarization direction of the incoming beam and of the analyzer being modified in time relative to one another, and the intensity changes produced thereby being evaluated by way of an evaluation device in order to determine the film thickness.

Abstract: To determine the visual range of, in particular, a driver in a motor vehicle, a contrast ((c(x1), c(x2)) is measured from at least two measuring positions (x1, x2) of a measuring device situated at different distances from the object, and the ratio of the measured contrast values is converted to a visual range (&dgr;), using the difference of the distances of the measuring positions from the object.

Abstract: A device, by which an unadulterated visibility range can be determined that is independent of the scattering-medium characteristics, determines according to the LIDAR principle the instantaneous visibility range from backscatter light reflected in the scattering medium in front of a vehicle. An evaluation unit is also provided which normalizes a plurality of backscatter measuring curves recorded in succession over time. It forms an average measuring curve from the normalized measuring curves, and derives from at least one measured value of the averaged measuring curve, a visibility range which is independent of the backscattering characteristics of the scattering medium. Using this visibility range thus ascertained, an adaptive compensation of the instantaneously ascertained visibility range is carried out in the evaluation unit.

Abstract: A device for inspecting surfaces includes a beam splitter which couples out, from an input radiation a first measuring radiation and a second measuring radiation. Both measuring radiations exhibit different properties. A first exemplary embodiment makes provision for the different property to be achieved by different polarization planes. Another exemplary embodiment makes provision for the different properties to be achieved by different wavelengths. The measuring radiations reflected by the surfaces are brought together by the beam splitter to form an output radiation which is fed to an optical receiving device. The device according to the present invention is mainly suited for inspecting surfaces in bores, especially, in blind-end bores.

Abstract: An optical drilling device using a laser beam (5), having an optical arrangement located in the beam path for guiding the laser beam (5) along a circular cutting path and a focusing lens system (6) located downstream from the arrangement and focusing the laser beam (5) onto a workpiece (7). Maintaining a simple design, the various parameters can be easily set by providing the optical arrangement with a separately rotatable image rotator (4) which guides the beam along the cutting path.

Abstract: An interferometric instrument for sensing the surfaces of a test object includes a radiation generating unit for emitting briefly coherent radiation and a first beam splitter for producing a first beam component and a second beam component. One beam component is aimed at the surface of the test object, and the other beam component is aimed at a device with a reflecting element for periodically changing the light path. The instrument also has an interference element which causes the radiation coming from the surface and the radiation coming from the device to interfere with one another, and a photodetector which receives the radiation. With a simple design, it is possible to increase the measuring accuracy by providing the device for changing the light path with an arrangement producing a parallel shift positioned in the optical path, followed by a stationary reflecting element.

Abstract: An integrated acoustooptical component for frequency-shifting optical frequencies is proposed, in which two separately guided optical waveguides exhibit an optical coupling region, which is designed in the manner of a directional coupler and in which the two optical waveguides exhibit a small spacing from one another generating an optical coupling. The acoustic waves of a sound generator propagate in the longitudinal direction over the coupling region. The two optical waveguides exhibit differing propagation constants for light. If, for example, light of mode a is injected into the optical waveguide and if the sound generator is energised, then the photons of mode a are scattered at the phonons of the acoustic waves and converted into mode b of the optical waveguide, where they can propagate. This gives rise to a frequency shifting. Accordingly, the acoustooptical component includes a frequency shifter and at the same time a coupler, which can be used for beam splitting and/or as an optical switch.