Results 271 to 280 of about 247,048 (296)

Focal plane arrays for millimeter-wavelength astronomy

1992 IEEE Microwave Symposium Digest MTT-S, 2003
Some of the general characteristics of focal plane imaging systems and associated optics are discussed. Detailed discussion is focused on the two large millimeter-wavelength focal plane arrays presently in operation: the 8-element 1.3-mm-wavelength NRAO array on the 12-m telescope and the 15-element 3-mm-wavelength array on the FCRAO (five College ...
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A new generation of SIS receivers for millimeter-wave radio astronomy

Proceedings of the IEEE, 1994
A new generation of low-noise, dual-polarization heterodyne receivers covering all atmospheric windows between 68 and 300 GHz has been developed for the 12-m telescope on Kitt Peak, AZ, operated by the National Radio Astronomy Observatory (NRAO). A modular approach to the receiver construction has been used.
John M. Payne, James W. Lamb, Jackie G. Cochran, Nancyjane Bailey   +3 more
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Multibeam receiver for millimeter-wave radio astronomy

Review of Scientific Instruments, 1988
An eight-beam receiver system for millimeter-wave radio astronomy is described. The receiver is designed to map spatially extended radio sources in both spectral line and continuum emission at a wavelength of 1.2 mm. This receiver is now in use on the 12-m radio telescope on Kitt Peak in Arizona.
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Millimeter radio astronomy as a probe for convective zone of the Sun

2010 INTERNATIONAL KHARKOV SYMPOSIUM ON PHYSICS AND ENGINEERING OF MICROWAVES, MILLIMETER AND SUBMILLIMETER WAVES, 2010
Relatively low spatial resolution of not great millimeter radio-telescopes narrows the range of available tasks in the field of solar physics. However, there are large scale phenomena on the Sun hidden among fine details of hires images. For example, the global distribution of solar activity is apparently connected with the processes in the depths of ...
O.V. Arkhypov, A.V. Antonov
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A Brief Overview of Millimeter-Wave Astronomy

1999
Even in today’s specialized world, individual fields are so broad that they cannot be adequately represented within the limit of a few pages. Millimeter-wave astronomy is no exception. Nevertheless, I will attempt to give a reasonable overview of this rapidly-growing field within such a limit.
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Switching subreflector for millimeter wave radio astronomy

Review of Scientific Instruments, 1976
A method of beam switching a Cassegrain antenna used for radio astronomy by tilting the hyperbolic secondary reflector is described. The system described has been in use for over a year at the 11-m millimeter wave antenna operated by the National Radio Astronomy Observatory at Kitt Peak, Arizona.
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An 8 GHz digital spectrometer for millimeter-wave astronomy

SPIE Proceedings, 2012
We have designed and tested a digital spectrometer suitable for analyzing 8 GHz baseband signals. It is based on a 16- Gsps, 5-bit ADC from e2v and a Stratix-IV FPGA employed for later filtering and signal processing. Digitized data is received and synchronized via twenty high-speed 4-Gbps transceivers integrated in the FPGA.
Roberto G. García, Olivier Gentaz, Maryse Baldino, Marc Torres   +3 more
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Millimeter Radio Astronomy and the Solar Convection Zone

PLANETARY RADIO EMISSIONS VII, 2011
The global distribution of solar surface activity (active regions) is connected with processes in the convection zone. To extract the information on large-scale motions in the convection zone, we study the solar synoptic charts (Mount Wilson 1998-2004, Fe I, 525.02 nm). The clear indication of large-scale (= 18°) turbulence is found.
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New Directions for Millimeter Astronomy in the 21st Century

1994
To advance beyond the impressive achievements of the current generation of mm and sub-mm elescopes, an obvious step for astrophysics in the 21st century is construction of an array with ten times the collecting area of existing mm telescopes. This means ~ 10000 m2, equivalent to the collecting area of the Effelsberg 100 m telescope or the VLA, but ...
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Design considerations for a multibeam receiver for millimeter wave astronomy

International Journal of Infrared and Millimeter Waves, 1987
A progress report was given for a multibeam system with only a limited (3–4) number of beams. We have outlined the desirability of larger arrays and some instrumental consquences were considered. We have also shown that extension of the JCMT infrastructure could fulfil the requirements but most of the development need to be done in the frontend segment.
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