extended source

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source, extended 

A source consisting of many point sources separated laterally and such that it has a very low degree of coherence. Thus, an extended source has a given size and subtends a given angle. See coherent sources; beam of light; diffuse light.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann
References in periodicals archive ?
To quantify SpIOMM's ability to provide scientifically useful absorption spectra of an extended source, we targeted the giant elliptical galaxy M87 using SpIOMM's custom V filter (538-649 nm).
This instrument, attached to the 1.6 m telescope of the Observatoire du Mont-Megantic, is capable of obtaining seeing-limited, spatially resolved spectra of extended sources in filter-selected bandbases of the visible (350-900 nm) in a 127 x127 field of view with a spectral resolution R ~ 10-25000.
Exclusive properties of the code design needed by system in [18] on comparison with the standard LDPC code are that (1) the extended source nodes and extended check nodes should be placed at the end in order to allow for puncturing within binary erasure channel; (2) in addition to the extended source nodes, other source nodes connected to the extended check nodes should have one to one connection as shown in Figure 3.
It is very hard to place both extended source nodes and syndrome nodes at the end with independent check node equation for a specified BER parameter.
Experimental and simulated efficiency of a HPGe detector with pointlike and extended sources. Nucl Instrum Meth A 2002; 487:477-487.
Rolland, "Designing freeform reflectors for extended sources," in 6th Nonimaging Optics: Efficient Design for Illumination and Solar Concentration, vol.
Scene generation -- the third level of simulation -- excels at modeling extended sources and entire scenes.
As of this writing, the positions and brightness of 162 million point sources (mainly stars) and 600,000 extended sources (mainly galaxies) were available online.
Shirley, Revised formulas for diffraction effects with point and extended sources, Appl.
extended sources there is frequently a tiny radio source located at the nucleus of the galaxy in question.
A reticle with half the disk 50% transmissive, as shown in Figure 3,(3) tends to give extended sources (such as clouds) a direct current (DC) signal while retaining the pulsed signal from point (target) sources.
That's because most natural emissions come from extended sources on the sky.

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