Abstract: An image-capturing device contains a housing and a camera accommodated in the housing in particular for continuous image capturing and the generation of corresponding image data. Accordingly, the camera is a thermal-imaging camera for capturing thermal images. At least one part of the housing lying in the field of view of the thermal-imaging camera or a part of the housing embodied as an optical lens is constructed such that the part is at least substantially transparent in the infrared range and nontransparent, in particular opaque, in the optically visible range. According to one particular embodiment, the image-capturing device is configured as a person-counting mechanism.

Abstract: A method and a system evaluate a security situation in a building. The building has accommodation areas with access authorization for authorized persons. A count of the persons present in the accommodation areas is determined in that, in a radio network which contains a plurality of radio stations arranged spatially distributed in the ceiling, wall or floor, the influencing of the radio field of the radio stations between one another by persons physically present there is evaluated, by a radio tomographic location and detection method. A current count of identifiers which are read by RFID reading devices of RFID transponders is determined, the identifiers being carried by authorized persons. The RFID reading devices are arranged there spatially distributed in the ceiling, wall or floor. Based on the respective counts of personal identifiers and the determined person count, an indicator for evaluating the current security situation in the building is determined.

Abstract: A sequence of video images is generated of a pavement area of an airport which contains one or more objects. A processor accesses a background model of the pavement area and determines in a current image a single cluster of foreground pixels that is not part of the background model and assigns a first value to each foreground pixel in the cluster to create a foreground mask. The background model is updated by learning new conditions. A convex hull is generated from the foreground mask. A ratio is determined from pixels captured by the complex hull and pixels in the foreground mask. A ratio higher than a threshold value indicates an object not being an airplane and an alert is displayed on a computer display. Images may be thermal images. A surveillance system based on the calculated ratio is disclosed.

Abstract: An image-capturing device contains a housing and a camera accommodated in the housing in particular for continuous image capturing and the generation of corresponding image data. Accordingly, the camera is a thermal-imaging camera for capturing thermal images. At least one part of the housing lying in the field of view of the thermal-imaging camera or a part of the housing embodied as an optical lens is constructed such that the part is at least substantially transparent in the infrared range and nontransparent, in particular opaque, in the optically visible range. According to one particular embodiment, the image-capturing device is configured as a person-counting mechanism.

Abstract: A method and a system evaluate a security situation in a building. The building has accommodation areas with access authorization for authorized persons. A count of the persons present in the accommodation areas is determined in that, in a radio network which contains a plurality of radio stations arranged spatially distributed in the ceiling, wall or floor, the influencing of the radio field of the radio stations between one another by persons physically present there is evaluated, by a radio tomographic location and detection method. A current count of identifiers which are read by RFID reading devices of RFID transponders is determined, the identifiers being carried by authorized persons. The RFID reading devices are arranged there spatially distributed in the ceiling, wall or floor. Based on the respective counts of personal identifiers and the determined person count, an indicator for evaluating the current security situation in the building is determined.

Abstract: A sequence of video images is generated of a pavement area of an airport which contains one or more objects. A processor accesses a background model of the pavement area and determines in a current image a single cluster of foreground pixels that is not part of the background model and assigns a first value to each foreground pixel in the cluster to create a foreground mask. The background model is updated by learning new conditions. A convex hull is generated from the foreground mask. A ratio is determined from pixels captured by the complex hull and pixels in the foreground mask. A ratio higher than a threshold value indicates an object not being an airplane and an alert is displayed on a computer display. Images may be thermal images. A surveillance system based on the calculated ratio is disclosed.

Abstract: The functional suitability of video monitoring devices which have at least one camera (8) is checked by means of a measurement device which has a processor (4), and by means of an analysis tool (7) which can be implanted in the processor (4). In this case, the images which are supplied from the at least one camera (8) are analyzed for parameters which are characteristic of the respective function. The analysis tool (7) is formed essentially by software which comprises two modules (5, 6), with one module (5) being provided for the application-specific configuration of the software and containing significant parameters for the current or intended application. The other module (6) is provided for the analysis of the images which are supplied from the at least one camera (8), during which analysis the quality of the images is assessed with respect to the said parameters.

Abstract: A detector device for detecting the presence of airborne particles such as smoke includes a light source, an optical bridge, a measurement path, a reference path, a measurement receiver and a reference receiver. The optical bridge, in addition to the light source and the measurement and reference receivers, are the only optical elements of the detector device. The optical bridge includes two circular apertures arranged downstream of the light source along the radiation path. The light source is arranged in a chamber having an air reservoir, whose surface area is substantially greater than that of the light source. A temperature drift curve is determined by heating the light source and storing the detector signal at different temperatures.

Abstract: A passive infrared intrusion detector for the detection of infrared body radiation includes a sabotage detector, in particular for detecting spraying of the entrance window of the intrusion detector. The sabotage detector includes a light source, a corresponding light sensor, and an optical diffraction grating structure on the outside of the entrance window. The light source and the light sensor can be on the same or on opposite sides of the entrance window. By first- or higher-order diffraction, light from the light source is focused onto the sensor, and a resulting electrical signal from the sensor is evaluated by an evaluation circuit. In case of sabotage, the focusing effect of the optical diffraction grating structure vanishes, so that the light intensity at the detector is reduced. The drop in light intensity triggers a sabotage alarm signal.

Abstract: In a technique for detecting organic vapors and aerosols, e.g. of amines, hydrazines and nitrogen-containing compounds produced in combustion, molecules condense at a surface of a conductive device. By heating the conductive device in pulsed fashion, e.g. by resistance heating, condensed molecules are thermally ionized and emitted from the conductive device. Emitted ions are collected by a collector electrode, and the resulting ionic current pulse is amplified by a transimpedance circuit. The heat pulse lasts until the ionic current pulse has subsided, by which time the conductive device has become free of residual substances. As a result, the conductive device remains uncontaminated and has a long service life. The time-averaged power consumption of the technique is less than 2 mW. For resistance heating, a meander heater element can be disposed on a silicon nitride membrane across an etched opening in a silicon chip.

Abstract: In an infrared intrusion detector, a focusing mirror reflects incident infrared radiation of interest onto a pyroelectric sensor element. To prevent extraneous radiation from reaching the sensor element, the mirror has a reflective layer for reflecting infrared radiation of interest, and an absorptive layer disposed behind the reflective layer for absorbing extraneous radiation which has passed through the reflective layer. Infrared radiation of interest includes human body thermal radiation, and extraneous radiation includes the visible spectrum. Doped indium-tin oxide (ITO) is preferred for the reflective layer.

Abstract: A device (7) for testing the operation of smoke detectors (3) has a housing (1) which is open at one end and can be placed over the smoke detector (3). A test light source (5) in the housing provides light pulses which radiate into the inside of the smoke detector (3) under test. The test device also has a test light detector (4) that receives light coming from the smoke-indicating light source (15) of the smoke detector (3) and controls the test light source (5) in relation to the received light. The light pulse of the test light source (5) is received by the smoke-indicating light detector (14) of the smoke detector (3). By checking if the smoke detector (3) goes into the alarm state, it can be ascertained whether it is in an operational condition.

Abstract: Optical smoke detectors such as extinction smoke detectors and scattered-light smoke detectors include a radiation source, a radiation detector or receiver, and a measurement volume which is in communication with ambient atmosphere and which is traversed by a light path from the radiation source to the radiation receiver. For compactness and simplicity, such an optical smoke detector is provided with a planar-optical element in the optical path. Suitable as planar-optical elements are diffractive elements, e.g., holographic-optical elements (HOE), and micro-Fresnel elements (MFE), e.g., micro-Fresnel reflectors (MFR).