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A composite video signal combines, on one wire, the video information required to recreate a color picture, as well as line and frame synchronization pulses. The color video signal is a linear combination of the luminance (Y) of the picture and a chrominance subcarrier which carries the color information (C), a combination of hue and saturation .
The phase velocity is the rate at which the phase of the wave propagates in space. The group velocity is the rate at which the wave envelope, i.e. the changes in amplitude, propagates. The wave envelope is the profile of the wave amplitudes; all transverse displacements are bound by the envelope profile.
The IRE unit is used in the measurement of composite video signals. Its name is derived from the initials of the Institute of Radio Engineers. [1] A value of 100 IRE is defined to be +714 mV in an analog NTSC video signal. A value of 0 IRE corresponds to the voltage value of 0 mV, the signal value during the blanking period.
A vectorscope is a special type of oscilloscope used in both audio and video applications. [1] Whereas an oscilloscope or waveform monitor normally displays a plot of signal vs. time, a vectorscope displays an X-Y plot of two signals, which can reveal details about
The coherence time, usually designated τ, is calculated by dividing the coherence length by the phase velocity of light in a medium; approximately given by = where λ is the central wavelength of the source, Δν and Δλ is the spectral width of the source in units of frequency and wavelength respectively, and c is the speed of light in vacuum.
In this simple sinusoidal example, the constant θ is also commonly referred to as phase or phase offset. φ(t) is a function of time; θ is not. In the next example, we also see that the phase offset of a real-valued sinusoid is ambiguous unless a reference (sin or cos) is specified. φ(t) is unambiguously defined.
where ξ is the Iribarren number, is the angle of the seaward slope of a structure, H is the wave height, L 0 is the deep-water wavelength, T is the period and g is the gravitational acceleration. Depending on the application, different definitions of H and T are used, for example: for periodic waves the wave height H 0 at deep water or the ...
A system undergoing slow time variation in comparison to its time constants can usually be considered to be time invariant: they are close to time invariant on a small scale. An example of this is the aging and wear of electronic components, which happens on a scale of years, and thus does not result in any behaviour qualitatively different ...