Questions tagged [radio-telescope]

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

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5
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1answer
59 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 "...
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1answer
184 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 ...
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1answer
69 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 ...
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1answer
35 views

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

This answer summarizes the contribution of the RadioAstron mission, a VLBI collaboration of radio telescopes using the Spectr-R space-based 10 m dish in high Earth orbit to produce "very-VLBI&...
7
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1answer
312 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 ...
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1answer
68 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)...
2
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1answer
53 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 ...
4
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1answer
59 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 ...
4
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1answer
59 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 ...
3
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1answer
54 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, ...
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1answer
129 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 ...
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4answers
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?
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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 ...
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2answers
51 views

Opening VLA Export Format data on Windows

I recently downloaded some data from the NRAO archive. It came as a file in the "VLA export format" with the extension .xp1. From what I gather I can open this using some software called ...
3
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1answer
60 views

Maritime telescopes: Stabilisation requirements for optical vs. radio telescopes?

SOFIA stands for Stratospheric Observatory for Infrared Astronomy. She says: My telescope stays stable with a spherical bearing, shock absorbers, and gyroscopes. I suppose a similar system would ...
3
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1answer
92 views

Current topics on Radio Astronomy and looking for advice

Background and Question: I'm an undergraduate student interested on Radio Astronomy. I consider myself enthusiastic about it and I project myself following this "path" so I'd like, ...
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2answers
109 views

Do ASKAP and ALMA have “fast dump” interferometric modes? Can they see and perhaps report Fast Radio Bursts in real time?

Chatterjee et al 2017 The direct localization of a fast radio burst and its host nicely shows a VLA detection of a repeating FRB in 5 millisecond steps nicely demonstrating the dispersion slope ...
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1answer
38 views

The role of 'the interference of waves' in VLBIs'

I've been trying to find out how VLBIs work. It says in this book I've read that many radio telescopes around the world work in tandem to use the interference of waves to get a clearer picture of ...
52
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4answers
6k views

Is there any role today that would justify building a large single dish radio telescope to replace Arecibo?

It seems that most of the modern radio astronomy instruments and observation that make the news are interferometers or phased array systems of one kind of another. Is there any application left for ...
5
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1answer
671 views

Building a floating, ocean-going giant radio telescope?

Given the loss of the Arecibo telescope: Is anybody aware of any efforts or studies towards a floating, ocean-going radio telescope of with 500m diameter or more? The idea is floating (pun intended) ...
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1answer
53 views

Hypothetical CMB space telescope design problem, received power from extended thermal source versus receiver front end NEP?

Consider the example of a large radio dish antenna in space equipped with a heat shield protecting it from the Sun. Let's say the amplifiers front-end effective temperature (for purposes of noise ...
3
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2answers
480 views

Is it possible to filter radio-waves using another radio telescope?

When making an observation using a radio telescope, is it possible to filter out noise coming out from a known source by using another telescope that will focus on that noise source? By filtering, I ...
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0answers
219 views

How could the loss of the Arecibo Observatory have been prevented?

Would more preventative maintenance, more regular inspection of the cables have helped? Robotic/drone inspection systems? Could the right robotic system have done work to save it in the last few ...
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4answers
3k views

What will succeed the Arecibo Observatory?

Just a few minutes ago, I got a notification from Space.com stating that the Arecibo Observatory will be, sadly, decommissioned due to extensive damage to its structure. So, with the loss of one of ...
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198 views

How accurately could late 50s - early 60s humans have mapped the solar system?

What if early SETI investigations had focused on our own solar system, rather than distant stars? Given the technology that existed around the 1950s, how much surveillance would humanity be able to do?...
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1answer
187 views

Is there an IRAM satellite that measures thermal radiation at 250 GHz, or was this a ground-based instrument?

The Nature Research Letter A Pluto-like radius and a high albedo for the dwarf planet Eris from an occultation (also here and here) says about half-way through: We now reassess Eris’ surface ...
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25 views

Software for simulating/calculating a known EMW pulse propagating in ISM, including dispersion, scattering, etc

Could you please let me know, if there is any software/code/tool for simulating/calculating the result of a short EMW pulse (waveform is exactly known) propagating in the ISM for long distance, ...
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1answer
79 views

How far can we detect lightning in radioastronomy?

The wikipedia article on whistlers has this information: Voyager 1 and 2 spacecraft detected whistler-like activity in the vicinity of Jupiter known as "Jovian Whistlers", implying the ...
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172 views

Is there an advantage to the equatorial region of the far side of the moon for a radio telescope or would any crater on the far side work?

If nearly any crater on the far side of the moon will work, and not just equatorial craters, then we could pick craters near the possible future Artemis base at the South pole which would allow easier ...
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36 views

How can I determine the location of an object for one observer given the location for another?

I know an object exists at the location of the beam-pointing-center of a radio telescope. I know the elevation/azimuth of the beam pointing center, as well as it’s “location” in galactic coordinates. ...
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1answer
311 views

How is the field of view of a radio telescope determined?

It’s my understanding that radio telescopes can only receive signals that hit the dish within a certain range of angles. How is that angular range determined i.e. measured and/or calculated?
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1answer
70 views

How can I correct for transit time?

I know the exact time a radio telescope detected a transient event. I also know the exact location of the telescope, and the galactic coordinates (galactic longitude, latitude) and right ascension and ...
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1answer
60 views

What is the role of the mesh on which dipole elements of the MWA antennas are placed?

I was reading about the radio telescope - Murchison Widefield Array (MWA) situated in Western Australia. Antennas of this telescope are quite unique and different from the usual dish radio telescope. ...
2
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1answer
82 views

How is Cosmic Microwave Background's temperature measured?

How do Cosmic Microwave Background missions/telescopes measure CMB temperatures? I understand that CMB has Planck's spectrum. So I was thinking one strategy could be to measure the spectral radiance ...
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Is there work underway to push the long baseline capabilities of the Event Horizon Telescope to sub-millimeter wavelengths?

The Max Planck Institute for Radio Astronomy's press release Something is Lurking in the Heart of Quasar 3C 279; First Event Horizon Telescope Images of a Black-Hole Powered Jet shows a stunning ...
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1answer
68 views

Why do radio telescopes, but not shorter wavelengths, have this Big Data problem?

Only with new radio telescope arrays like ALMA and SKA, have I heard of this "problem" with too much data come up. Too big to store. That one cannot archive it all for future studies, but that one has ...
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2answers
158 views

What was the field of view of the Ohio State University Radio Observatory of Wow! signal fame?

This answer to Did comets 266P/Christensen or P/2008 Y2 (Gibbs) cause the Wow! signal? points out that the comets in question were nowhere near where the radio telescope was pointed. Wikipedia says ...
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0answers
78 views

Open dataset from antenna array

I am looking for a raw radio-astronomic antenna array dataset of relatively modest size (on the order a few MB, or even less), to evaluate a data processing algorithm. The dataset ideally should be ...
2
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1answer
70 views

What might some examples be of radio telescope interferometric arrays made from “cheap components relying on massive computing power”?

This answer mentions that there are some interferometric radio telescope arrays ...consisting of very cheap components relying on massive computing power to retrieve the signals from noise... The ...
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0answers
59 views

Feasibility of radioastronomy in densely populated areas

In general, radioastronomy as well as optical astronomy depend on a good SNR. This meant to position telescopes as far as possible from noise sources. Optical telescopes were built at elevated points ...
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0answers
68 views

Would radio telescope located anywhere within a 100 light year radius detect our radio emissions? [duplicate]

If there was a radio telescope, as sophisticated as our best radio telescopes within a 100 light year radius from earth. AND if its sole purpose was search for signs of artificial/intelligent radio ...
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0answers
110 views

How did Arecibo make radar images of ice on Mercury's poles?

update: I still haven't been able to get my hands on the Icarus paper linked below (I'll try other libraries) but these are newer and quite interesting!: Constraining the thickness of polar ice ...
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1answer
40 views

Need some sources on radiotelescope sensitivity

Could anyone direct me to papers with info on minimal flux that can be registered with radiotelescopes?
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1answer
45 views

What determines the surface material of the ALMA and Spitzer telescope?

The transition between metal dish and mirror happens around hundreds of microns. For example, the shortest wavelength the ALMA(metal dish) can detect is about 0.3mm, while the longest wavelength the ...
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1answer
74 views

How do radio telescopes gather information about visible light?

Is the first image of a black hole that was captured by the Event Horizon Telescope what would be seen with a large enough optical telescope (or with the naked eye from a proper distance of the black ...
7
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3answers
818 views

Why does the Event Horizon Telescope (EHT) not include telescopes from Africa, Asia or Australia?

The Event Horizon Telescope seems to include these radio telescopes currently: Image by European Southern Observatory (ESO)/O. Furtak; CC-BY 4.0-licensed, see the source on Wikipedia Commons and the ...
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1answer
170 views

Event Horizon Telescope Data Cleanup

I was wondering how the researchers were able to minimize or neutralize confirmation bias regarding the data collected? As I understand it, the algorithm pruned much of the data, which would make ...
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1answer
220 views

Does the “photo of a black hole” taken by EHT actually depict a visible light-based scenario?

I'm still at my bachelor of electronic and communications engineering, so I'm not an expert of radiotelescopes; however, I surely know that, typically, radio communications are characterized by a RX ...
7
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2answers
517 views

What part of the EM spectrum was used in the black hole image?

The EHT has published the first image of a black hole. It is the event horizon of the singularity in M87 against its accretion disk. I've been through the reports in the popular press but none ...
5
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3answers
276 views

How can the Event Horizon Telescope image Sgr A* when it's not visible from all sites at one time?

I went to https://eventhorizontelescope.org/array and read about the ten sites listed as part of the EHT, I have a mashed-up screen shot of them below. I made a little script also shown below with ...