nulling interferometry

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nulling interferometry

[¦nəl·iŋ ‚in·tə·fə′räm·ə·trē]
(optics)
A technique in which light waves from a bright object such as a star are made to interfere and cancel each other in an optical system, allowing the observation of much fainter nearby objects that would otherwise be invisible in the glare of the bright object.
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References in periodicals archive ?
It is the first time the Keck Interferometer Nuller instrument has identified such a compact cloud around a star so far away.
In April 2007, the team simultaneously pointed both Keck telescopes at the star 51 Ophiuchi, or 51 Oph, and used the Interferometer's Nuller, a technique to combine the incoming light in a particular way, to block the unwanted starlight of 51 Oph and measure faint adjacent signals from the dust cloud surrounding the star.
The successful definition of the requirements in this review puts us on firm footing to proceed with further advancement of our space router, laser communications, and communications-on-the-move nuller technologies," said Stuart Linsky, program manager, transformational communications for Northrop Grumman.
The nuller antennas resist jamming from within their respective coverage areas by changing their gain patterns when a jamming signal is detected.
The BFN is a major component of the nuller subsystem, which provides anti- jam capabilities, a key function of the AEHF network that enables all branches of the U.
The MDR antennas consist of eight narrow spot-beam antennas: six distributed user coverage antennas (DUCAs), and two narrow spot beams with nulling capabilities, known as nuller antennas.
Four nullers are currently on orbit aboard two MILSTAR spacecraft, and the last two nullers will launch this month on MILSTAR Flight 6.
Both the nullers and the DUCAs provide 44 GHz uplinks and 20 GHz downlinks to the regions of Earth within their coverage area.