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To avoid the response masking important radar targets behind the beacon, racons only operate for part of the time. In the United Kingdom , a duty cycle of about 30% is used — usually 20 seconds in which the racon will respond to radar signals is followed by 40 seconds when it will not, or sometimes 9 seconds on and 21 seconds off (as in the ...
[citation needed] In 1973, the 450 RA/TA wireless microphone system, designed for TV news, is the first to enable reporters to move more than 1000 feet from the camera. [ citation needed ] In 1975, The Comrex wireless cue system, composed of the CTA cue transmitter and the CRA (now LPQRA) receiver, enables field reporters and producers to hear ...
Minimum resolvable temperature difference (MRTD) is a measure for assessing the performance of infrared cameras, and is inversely proportional to the modulation transfer function. Typically, an operator is asked to assess the minimum temperature difference at which a 4-bar target can be resolved. This minimum difference will change with the ...
Horizontal scan rate, or horizontal frequency, usually expressed in kilohertz, is the number of times per second that a raster-scan video system transmits or displays a complete horizontal line, as opposed to vertical scan rate, the number of times per second that an entire screenful of image data is transmitted or displayed.
Forward-looking infrared (FLIR) cameras, typically used on military and civilian aircraft, use a thermographic camera that senses infrared radiation. [1] The sensors installed in forward-looking infrared cameras, as well as those of other thermal imaging cameras, use detection of infrared radiation, typically emitted from a heat source (thermal ...
Frequency response. In signal processing and electronics, the frequency response of a system is the quantitative measure of the magnitude and phase of the output as a function of input frequency. [1] The frequency response is widely used in the design and analysis of systems, such as audio and control systems, where they simplify mathematical ...
Originally developed to show the camera's view to more people than the one looking through the eyepiece, today video assist is the name of a complex system, consisting of monitors, recorders, video transmitters, video switchers, IT and RF equipment, and hundreds of yards of cables. The video assist crew—the video assist operator, assistant ...
Photomultiplier tubes (photomultipliers or PMTs for short) are extremely sensitive detectors of light in the ultraviolet, visible, and near-infrared ranges of the electromagnetic spectrum. They are members of the class of vacuum tubes, more specifically vacuum phototubes. These detectors multiply the current produced by incident light by as ...