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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 ...
Minimum resolvable temperature difference. 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.
Frequency response requirements differ depending on the application. [6] In high fidelity audio, an amplifier requires a flat frequency response of at least 20–20,000 Hz, with a tolerance as tight as ±0.1 dB in the mid-range frequencies around 1000 Hz; however, in telephony, a frequency response of 400–4,000 Hz, with a tolerance of ±1 dB ...
A spectrum analyser – typically used as the measuring instrument in two-tone testing. Two-tone testing is a means of testing electronic components and systems, particularly radio systems, for intermodulation distortion. It consists of simultaneously injecting two sinusoidal signals of different frequencies (tones) into the component or system.
Modal testing is the form of vibration testing of an object whereby the natural (modal) frequencies, modal masses, modal damping ratios and mode shapes of the object under test are determined. A modal test consists of an acquisition phase and an analysis phase. The complete process is often referred to as a Modal Analysis or Experimental Modal ...
A spectrum analyzer measures the magnitude of an input signal versus frequency within the full frequency range of the instrument. The primary use is to measure the power of the spectrum of known and unknown signals. The input signal that most common spectrum analyzers measure is electrical; however, spectral compositions of other signals, such ...
An initial SFRA test is carried out to obtain the signature of the transformer frequency response by injecting various discreet frequencies. This reference is then used for future comparisons. A change in winding position, degradation in the insulation, etc. will result in change in capacitance or inductance thereby affecting the measured curves.
Diffuse field acoustic testing is the testing of the mechanical resistance of a spacecraft to the acoustic pressures during launch. In the aerospace industry, acoustic chambers are the main facilities for such tests. A chamber is a reverberant room that creates a diffuse sound field and is composed of an empty volume (from 1 m 3 to 2900 m 3 ...