Questions tagged [radio-telescope]

Questions related to the instruments used to perform observations in the radio frequency range.

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What on-site equipment is installed with radio telescopes?

I hope this question isn't too broad. I'd like to know something about radio telescopes, precisely what equipment they have. When I search "radio telescope control room" in image search ...
john_smith's user avatar
2 votes
2 answers
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Could we hear alien radio transmissions using radio interferometry?

Suppose money and engineering wasn't a concern. Could we actually build a bunch of radio telescopes in space, and use radio interferometry, so that we could actually hear the sort of radio ...
Adrian's user avatar
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Calculate change in spectral line intensity for a change in temperature

I am trying to do some simple modelling of spectral line emission. I am starting with some ALMA observations of a protoplanetary disk, where the emission from a particular molecule at frequency 344GHz ...
lucas's user avatar
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5 votes
1 answer
555 views

Would it be possible to use existing radio-telescopes to do spot measurements of CMB?

With CMB peaking at roughly 158GHz would it be possible to create a more precise map of CMB just by sampling 'points' using existing Earth-based radio telescopes? I understand that large dish ...
user2820052's user avatar
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1 answer
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is there any site with historical radiotelescope data about observations 21 cm line Hydrogen (1.42 GHz)?

I am looking for an open source that contain historical raw data or (meta)data about historical observations of the 21 cm line hydrogen made via radio telescopes.
Rad's user avatar
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25 votes
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Why are radio telescopes often built into natural depressions?

Radio telescopes are often built into sink holes or natural depressions in the landscape.* This is opposed to optical telescopes which are usually placed on mountains to avoid as much atmosphere as ...
joeyfb's user avatar
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2 votes
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How do we get -0.4 mJy/beam in the the 1.28 GHz MeerKAT Galactic Center Mosaic?

Dr. Becky's Feb. 11, 2022 video Move over JWST! 5 new telescopes to get excited for makes a quick mention of this image produced by the Meerkat array and published in Heywood et al. 2022 The 1.28 GHz ...
uhoh's user avatar
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6 votes
1 answer
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Do high power radar astronomers try to avoid beaming power at (at least some) artificial satellites as they pass overhead?

This answer to "Next Generation Arecibo Telescope (NGAT)... would combine a 314-metre-wide platform with a swarm of 9-metre dishes on top" What would that look like? links to an interesting ...
uhoh's user avatar
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20 votes
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"Next Generation Arecibo Telescope (NGAT)... would combine a 314-metre-wide platform with a swarm of 9-metre dishes on top" What would that look like?

In Nature News' August 11, 2023 Closing down an icon: will Arecibo Observatory ever do science again? found in The Observatory there is discussion of the Next Generation Arecibo Telescope (NGAT): ...
uhoh's user avatar
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4 votes
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Greetings to Altair: what is the probability of detecting a return message, assuming one was sent?

Greetings to Altair was a 1983 transmission to Altair, 16.7 light years distant, sent on the 46m Stanford radio telescope, known as "The Dish". [Quast 2018] Assuming an alien civilisation ...
Dragon's user avatar
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1 answer
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Measuring Expansion Rate of Crab Nebula with Radio Spectrum Scan

I am a high school student who is into radio astronomy, and I have the opportunity to use Green Bank’s 20m radio telescope for a practice research project. I would like to use my observations to very ...
Myra's user avatar
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3 votes
0 answers
70 views

Questions about the Cocconi Morrison paper on interstellar communication

I have been reading the paper by Cocconi and Morrison on interstellar communication and I have trouble understanding their formulas. The paper begins by stating, that a star similar to the quiet sun ...
Alexander Cska's user avatar
3 votes
0 answers
93 views

How will China's Xuntian space telescope use its Terahertz capability? THz Spectroscopy? Imaging? Something else?

An Update on the Chinese Space Station Telescope Project Hu Zhan, National Astronomical Observatories, CAS, KIAA, Peking University, On behalf of the CSST Team, ISSI-BJ Workshop: Weak gravitational ...
uhoh's user avatar
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5 votes
2 answers
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Are there any new/latest/recent radio sky surveys' data release which is publicly accessible?

There are many sky surveys that have been conducted by telescopes in different wavelengths of the electromagnetic spectrum like DSS (Digitized Sky Survey), SDSS (Sloan Digital Sky Survey), WISE (wide-...
Dhruv Nayak's user avatar
2 votes
1 answer
110 views

What's the formula of SNR (Signal to Noise Ratio) to dipole antenna array (eg, LOFAR) look like?

It was wellknown that the SNR of single dish telescope reads $$s/n=P_s/P_n=\frac{P_s}{T_n}\sqrt\frac{t}{B},$$ where $P_s$ is the collected power, $T_n$ the noise temperature, $t$ the measure time and $...
Hunter's user avatar
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1 vote
3 answers
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How does Very Long Baseline Interferometry work?

According to internet sources, this technique increases the effective diameter of the telescope, thus improving the angular resolution of the telescope. However I don't understand how this actually ...
Ambica Govind's user avatar
7 votes
1 answer
152 views

SKA 101: How will it "perform the most precise tests of Einstein's theories" and Australia & South Africa arrays be "made to work seamlessly together"

The BBC's December 7, 2022 SKA: Construction to begin on world's biggest telescope includes the following: It will perform the most precise tests of Einstein's theories and The first major ...
uhoh's user avatar
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2 votes
0 answers
88 views

We are making a 5 meter diameter radio telescope dish by using metal mesh and need some advice and/or reference designs [closed]

We are making a 5 meter diameter radio telescope dish. What metal should we use and what must be the size of the mesh if the targeted frequency is 1430 Hz? Also what might a simple but stable ...
killbox72's user avatar
1 vote
0 answers
56 views

What's the most distant radio message we could detect with today's radio telescopes, if the message is initially broadcasted in all directions?

An additional assumption is that broadcasting the message may require using a medium-sized star, like the Sun, for an hour, by e.g. Dysoning it. I don't know enough to answer the question myself. If ...
Mark Smith's user avatar
2 votes
2 answers
121 views

In radio astronomy, do two dimensional sensors exist?

Is there an equivalent of CCD/CMOS sensors for non-optical wavelengths? (not looking for alternative/indirect methods like interferometry)
2080's user avatar
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3 votes
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What is the maximum distance we could detect incidental radio signals from aliens? [duplicate]

I've been getting interested in the Fermi Paradox discourse again, and something's been bugging me about the assumptions we could actually detect incidental radio signals from aliens, or vice versa. ...
Logan Shaw's user avatar
0 votes
1 answer
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Where can I get a step by step guide to use CASA for obtaining a radio image of a planet like say Jupiter?

I intend to use CASA for processing ALMA data for Jupiter and obtain a proper radio image for Jupiter. However, is there any specific step by step guide for the same just as is the following for TW ...
Dhruv Nayak's user avatar
6 votes
2 answers
97 views

In terms of results, how similar is a bunch of telescopes across the globe to an Earth-sized telescope?

The Event Horizon Telescope emulates an Earth-sized telescope by syncing a bunch of radio telescopes across the planet to do take pictures with a small enough angular resolution to take pictures of a ...
zucculent's user avatar
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2 votes
1 answer
57 views

How and where can I get the continuum and/or FITS data for Jupiter and Saturn from ALMA, GMRT and VLA Telescopes?

I intend to process and analyze the radio images and emissions from Jupiter and Saturn. I wish to get data from ALMA, GMRT and VLA Telescopes. Requesting you to please guide me as to how do I access ...
Dhruv Nayak's user avatar
6 votes
1 answer
139 views

Do circa 1 THz radio telescope front end amplifiers actually down convert before amplifying? At what frequency does amplification become untenable?

A discussion of how astronomers view where "radio" ends and "infrared" begins under What does the celestial sphere look like in thermal IR? led me to wonder just how high of a ...
uhoh's user avatar
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6 votes
2 answers
236 views

Why aren't concentrated solar power plants use for astronomical observations of some type?

Concentrated solar power plants use reflecting surfaces to gather the sun rays for energy production. Currently they sit idle at night and are not used for anything. These have huge collection areas, ...
H. Gunov's user avatar
13 votes
3 answers
2k views

How are radio telescopes pointed?

In the past, I worked as a programmer in a radio astronomy station, and since then I have a question on my mind. To observe a star with a telescope, we locate its location with our eyes and then we ...
Aminos's user avatar
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0 answers
273 views

Is it possible to make (or buy kit) DIY portable radio telescope that I can place on the balcony like optical telescope?

I want to have a small radio telescope to use on balcony instead of optical when sky is cloudy (it is very often). Is it possible? What objects can be observed by that telescope? Is it possible to use ...
Robotex's user avatar
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1 vote
1 answer
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If we put a radio telescope on Mars and use it in array with earth radio telescopes, how much will we able to see?

If we put a radio telescope on Mars and use it in array with earth radio telescopes, how much will we able to see? Will it allow us to see planets, like we do with black hole?
Robotex's user avatar
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0 votes
1 answer
46 views

TPoint software, INDAT command - Format 4 (ALTAZ)

I am working (in fact, trying to work) with TPoint for improving a solar telescope pointing calibration (SST, in Casleo, AR) and stumbled on the input data for INDAT command. SST is a multibeam solar ...
myrnayk's user avatar
1 vote
1 answer
106 views

How would the surface of Mars compare with the Atacama desert for millimeter wave (and shorter) radio astronomy?

In this answer to What kind of experiments would a scientist do on Mars? I suggest that the resemblance of the ALMA array's site in the Atacama Desert to the surface of Mars suggests millimeter ...
uhoh's user avatar
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6 votes
1 answer
119 views

Why Nyquist Sampling Rate depends on Bandwidth and not max frequency?

Is the Nyquist sampling rate same for different bands if those bands have same bandwith? E.g. Would the Nyquist Sampling rate be same for 1000-1400 MHz band as for 100-500 MHz band because both the ...
user307105's user avatar
6 votes
1 answer
1k views

rms noise, confusion and dynamic range in radio images

I have been trying to understand imaging in radio astronomy. Below are some of my questions related to it and my understanding of their answers. I am not very confident about my understanding of them ...
user307105's user avatar
1 vote
0 answers
55 views

How to properly compare radio to optical/NIR images?

I mainly work with radio continuum data and recently I started working on some HST hydrogen recombination line datasets to compare with the radio data that I have, but I'm very confused about what is ...
spacedog's user avatar
8 votes
2 answers
827 views

Is Carl Sagan's famous "snowflake" quote correct?

“The total amount of energy from outside the solar system ever received by all the radio telescopes on the planet Earth is less than the energy of a single snowflake striking the ground.” ― Carl Sagan,...
ZAB's user avatar
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3 votes
1 answer
172 views

How, precisely, do radio astronomers detect (and record) the phases of waves for interferometry?

Interferometry is always in the news, and at radio frequencies it has been for a long time... The popular press always talks about directly 'interfering' two waves as they come in, but can they tell ...
Kurt Hikes's user avatar
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3 votes
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What is notable about LOFAR's sub-arcsecond radio resolution of distant galaxies? Does lower freq. range enable new capabilities that mm wave can't?

The BBC's Astronomers see galaxies in ultra-high definition covers some news related to papers in Astronomy & Astrophysics' dedicated, open access issue Sub-arcsecond imaging with the ...
uhoh's user avatar
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5 votes
1 answer
294 views

If the visibility function is the Fourier transform of the sky brightness distribution, why do you need the dirty beam and dirty image to find it?

In radio astronomy, the dirty image is equal to the inverse Fourier transform of the uv-plane coverage times the sampled visibilities. The dirty image is also equal to the convolution of the "...
Astroturf's user avatar
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11 votes
1 answer
379 views

Do radio telescopes see other stars better at night?

As you know, we don’t see stars with the naked eye during the day because of the visible glare of our Sun. As I understand our Sun emits radio frequency waves, too. Is there a radio ‘glare’ from the ...
David's user avatar
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7 votes
1 answer
102 views

What could a cloud of mini radio dishes see?

Suppose an astronomer gave a 1 m radio dish to 500 people scattered over the face of the Earth and connected them to the internet. The people are directed to set their radio antennae up in their ...
jvriesem's user avatar
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0 votes
1 answer
77 views

Did the Spectr-R space-based radio telescope use on-board accelerometer to measure non-gravitational acceleration for baseline correction?

This answer to Why is space-based VLBI scattering sub-structure "Hopefully, a new promising tool to reconstruct the true image of observed background target(s)"? summarizes the contribution ...
uhoh's user avatar
  • 31.2k
7 votes
1 answer
915 views

What radio frequency ranges are most beneficial for astronomy?

I cannot get the idea of citizen radio astronomy out of my head, and choosing an antenna (design) heavily depends on the desired frequency range. The Arecibo telescope as my gold standard operated 300 ...
B--rian's user avatar
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2 votes
1 answer
105 views

Is Sofia a radio telescope proper?

I usually think of SOFIA, the Stratospheric Observatory for Infrared Astronomy as an infrared optical telescope: SOFIA uses a 2.5 m (8.2 ft) reflector telescope, which has an oversized, 2.7 m (8.9 ft)...
uhoh's user avatar
  • 31.2k
3 votes
1 answer
122 views

How can we install a radar on radio telescopes like FAST or GMRT?

Recently I came across an article mentioning that ever since the failure of Arecibo telescope, we only have one asteroid radar imaging telescope which is Goldstone observatory. The article also ...
Krishna K's user avatar
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4 votes
1 answer
1k views

What is the significance of the velocity resolution in spectral line observations using radio interferometry?

I've always struggled to conceptualize the term "velocity resolution" in spectral observations. In principle, it is simple to calculate. For example, one can take the spectral width and ...
Astroturf's user avatar
  • 1,111
4 votes
1 answer
105 views

What is the significance of using baseline pairs in radio interferometry?

Radio interferometry utilizes arrays of smaller telescopes that are linked together to synthesize a larger aperture telescope. Astronomical radio observatories, such as the Very Large Array in New ...
Astroturf's user avatar
  • 1,111
3 votes
1 answer
214 views

Open source library to calculate image from signals of a distributed set of radio dishes?

The National Radio Astronomy Observatory's Q&A "How To Make Images With a Radio Telescope" says The most straightforward way to make a radio image with your satellite antenna system, ...
B--rian's user avatar
  • 5,616
10 votes
1 answer
366 views

Can one build a distributed radio telescope?

I understand some radio telescopes are built as arrays of receivers. Could one build an array from a heterogeneous set of receivers in scattered locations? Suppose a large number of persons each ...
Joe Cooper's user avatar
28 votes
4 answers
5k views

Could we carve a large radio dish in the Antarctic ice?

Could we carve a large radio dish in the Antarctic ice that could replace the Arecibo Observatory? Could this work, and what would be some potential limitations?
Joe's user avatar
  • 511
8 votes
1 answer
247 views

Recommend a radio calibration target for amateur radio telescope

I have a small antenna and radio system that can receive frequencies between 1MHz and 1GHz. The system has a discone antenna. I plan to do some aperture synthesis based on the daily rotation of the ...
Craeft's user avatar
  • 283