scholarly journals Measuring the Linearity of Radio?Astronomy Receivers

1962 ◽  
Vol 15 (4) ◽  
pp. 572
Author(s):  
MM Komesaroff ◽  
DS Mathewson
Keyword(s):  
Point Source ◽  
Flux Density ◽  
Radio Astronomy ◽  
Noise Temperature ◽  
Low Noise ◽  
Receiver Noise ◽  
Large Telescopes

A convenient practice which is frequently adopted in observational radio 'astronomy is to express all aerial temperatures in terms of the temperature produced by a " point source" of known flux density. A difficulty with this procedure is that, with large telescopes and modern low-noise receivers, the aerial temperatures due to any of the better-known discrete sources are usually comparable with or greater than the receiver noise temperature.

scholarly journals A Tri-Band Cooled Receiver for Geodetic VLBI

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2662
Author(s):  
José A. López-Pérez ◽  
Félix Tercero-Martínez ◽  
José M. Serna-Puente ◽  
Beatriz Vaquero-Jiménez ◽  
María Patino-Esteban ◽  
...  
Keyword(s):  
Very Long Baseline Interferometry ◽  
Low Noise ◽  
Cryogenic Temperatures ◽  
Geospatial Information ◽  
Receiver Noise ◽  
Geodetic Vlbi ◽  
Long Baseline ◽  
Front End ◽  
X Band ◽  
Santa Maria

This paper shows a simultaneous tri-band (S: 2.2–2.7 GHz, X: 7.5–9 GHz and Ka: 28–33 GHz) low-noise cryogenic receiver for geodetic Very Long Baseline Interferometry (geo-VLBI) which has been developed at Yebes Observatory laboratories in Spain. A special feature is that the whole receiver front-end is fully coolable down to cryogenic temperatures to minimize receiver noise. It was installed in the first radio telescope of the Red Atlántica de Estaciones Geodinámicas y Espaciales (RAEGE) project, which is located in Yebes Observatory, in the frame of the VLBI Global Observing System (VGOS). After this, the receiver was borrowed by the Norwegian Mapping Autorithy (NMA) for the commissioning of two VGOS radiotelescopes in Svalbard (Norway). A second identical receiver was built for the Ishioka VGOS station of the Geospatial Information Authority (GSI) of Japan, and a third one for the second RAEGE VGOS station, located in Santa María (Açores Archipelago, Portugal). The average receiver noise temperatures are 21, 23, and 25 Kelvin and the measured antenna efficiencies are 70%, 75%, and 60% in S-band, X-band, and Ka-band, respectively.

A W-band low-noise amplifier with 22K noise temperature

2009 ◽  
Author(s):  
Eric W. Bryerton ◽  
Xiaobing Mei ◽  
Young-Min Kim ◽  
William Deal ◽  
Wayne Yoshida ◽  
...  
Keyword(s):  
Noise Temperature ◽  
Low Noise ◽  
Low Noise Amplifier ◽  
W Band ◽  
Noise Amplifier

scholarly journals Estimation of normalized point-source sensitivity of segment surface specifications for extremely large telescopes

2013 ◽  
Vol 52 (18) ◽  
pp. 4111 ◽  
Author(s):  
Byoung-Joon Seo ◽  
Carl Nissly ◽  
Mitchell Troy ◽  
George Angeli ◽  
Robert Bernier ◽  
...  
Keyword(s):  
Point Source ◽  
Large Telescopes

Laser light heating for low-noise temperature control in SQUID applications

2000 ◽  
Vol 284-288 ◽  
pp. 2111-2112 ◽  
Author(s):  
Charles E Cunningham ◽  
Tyce R DeYoung ◽  
Timaeus A Bouma
Keyword(s):  
Temperature Control ◽  
Laser Light ◽  
Noise Temperature ◽  
Low Noise

Multi-wavelength Optical Aperture Synthesis

1992 ◽  
Vol 10 (1) ◽  
pp. 71-73 ◽  
Author(s):  
R.G. Marson ◽  
T.R. Bedding ◽  
J.G. Robertson
Keyword(s):  
Radio Astronomy ◽  
Angular Resolution ◽  
Diffraction Limit ◽  
Double Star ◽  
Aperture Synthesis ◽  
Angular Diameter ◽  
Optical Aperture ◽  
Multi Wavelength ◽  
Red Giant ◽  
Large Telescopes

AbstractThe technique of aperture synthesis is well developed in radio astronomy. When applied to the optical regime, aperture synthesis allows one to partially overcome the blurring effects of the atmosphere and increase the angular resolution of large telescopes to the diffraction limit. MAPPIT (Masked APerture-Plane Interference Telescope) is a multi-element interferometer which operates at the coude focus of the 3.9 m Anglo-Australian Telescope. This instrument has recently been reconfigured to operate in a dispersed mode so that simultaneous observations in a band of wavelengths are possible. We will discuss this instrument’s new mode and present observations of the double star δ Sco and an angular diameter of the previously unresolved red giant β Gru.

A New Platform for Radio Astronomy Science Education

2021 ◽  
Vol 105 ◽  
pp. 179-183
Author(s):  
Guang Pu Yang ◽  
Liang Dong ◽  
Le Sheng He ◽  
Fa Xin Shen ◽  
Bin Tian ◽  
...  
Keyword(s):  
Science Education ◽  
High School Students ◽  
Radio Astronomy ◽  
Software Defined Radio ◽  
Electromagnetic Waves ◽  
Neutral Hydrogen ◽  
Low Noise ◽  
Public Understanding ◽  
School Students ◽  
Science Popularization

Radio astronomy telescope can get information from invisible universe by receiving electromagnetic waves. Difference from optical telescopes, there exists many difficulties for making the public understanding the radio astronomy phenomenon. In this paper, we will introduce a new platform for radio astronomy science popularization education in order to help public know radio telescope and radio astronomy. The platform consists of a 0.8meter parabolic antenna, a wide bandwidth low noise amplifier (LNA) and a Software Defined Radio (SDR) terminal. Based on SDR terminal which covers the band from 70MHz to 6GHz, we can get some strong emissions such as the Neutral hydrogen, solar radio bursts and so on in this band. People can carry out many radio astronomy experiments focusing on science popularization by this platform. This new science education tool can interest high school students in science and technology, also students can understand how radio telescopes works.

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