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The Square Kilometre Array

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#1 caballerodiez91

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Posted 15 November 2019 - 06:02 PM

As some of you probably know, the Square Kilometre Array will become the biggest radio telescope on Earth, with a collecting area of 1 square kilometre.

 

The construction will start in 2021 and the first light is expected to take place in 2027. It will cover the frequencies from 50 MHz to 15 Ghz.

 

But what I wanted to share with you guys is a new study about how far the SKA can 'listen'.

 

A recent study points out that the SKA could detect extraterrestrial airport radars 200 light years away.

 

Source: https://www.youtube....h?v=ayqyb8XCtE0

 

What do you guys think?



#2 TOMDEY

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Posted 15 November 2019 - 06:12 PM

The collecting area is far less than a square Km... but the resolution is determined by that diameter.    Tom



#3 nicoledoula

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Posted 15 November 2019 - 06:28 PM

As some of you probably know, the Square Kilometre Array will become the biggest radio telescope on Earth, with a collecting area of 1 square kilometre.

 

The construction will start in 2021 and the first light is expected to take place in 2027. It will cover the frequencies from 50 MHz to 15 Ghz.

 

But what I wanted to share with you guys is a new study about how far the SKA can 'listen'.

 

A recent study points out that the SKA could detect extraterrestrial airport radars 200 light years away.

 

Source: https://www.youtube....h?v=ayqyb8XCtE0

 

What do you guys think?

I understand antenna design and wave propagation, what's this thing supposed to be doing? How is the site powered? That's an admirable goal. (200 lt. yrs.) AFAIK space is completely filled with static. Must have some magic kind of filtering.........Us HAMs want to get our hands on that.


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#4 MikeTahtib

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Posted 15 November 2019 - 07:00 PM

I'm no radar expert, but I find it hard to believe it could pick up such faint signals from so far away.  I can't say that it can't, but it seems too easy.  I hope I'm wrong, and it can, though!  Any experts on the topic care to chime in?


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#5 nicoledoula

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Posted 15 November 2019 - 08:41 PM

  The Inverse Square Law is the mountain of an elephant in the room.  .Science says we should be skeptical of anything we can';t personally falsify. So I know I stand on solid ground regardless of the logically fallacious appeals and ad-hominem attacks that will undoubtedly be forthcoming. All the world is a stage.



#6 robin_astro

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Posted 16 November 2019 - 09:23 AM

The collecting area is far less than a square Km... but the resolution is determined by that diameter.    Tom

 

When (if) complete the SKA is indeed projected to have a total collecting area of 1 square kilometer. The effective aperture is much larger than this. (3000km)

 

[ 20% of total collecting area will be within 1 km diameter
[ 50% of total collecting area will be within 5 km diameter
[ 75% of total collecting area will be within 150 km diameter
[ Maximum baselines will be at least 3,000 km from array core.

 

From

 

https://www.skateles...rochure_web.pdf

 

A quick back of envelope check suggests detecting radar at 200lyr is not unreasonable. The specified sensitivity is 400 micro Janskys (A Jansky is 10^-26 W/m2)

 

 

A  1MW 5 degree wide beam for example could give that at 200lyrs

 

Of course this is not the prime purpose of the SKA

 

Robin


Edited by robin_astro, 16 November 2019 - 09:23 AM.


#7 TOMDEY

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Posted 16 November 2019 - 09:36 AM

When (if) complete the SKA is indeed projected to have a total collecting area of 1 square kilometer. The effective aperture is much larger than this. (3000km)

 

[ 20% of total collecting area will be within 1 km diameter
[ 50% of total collecting area will be within 5 km diameter
[ 75% of total collecting area will be within 150 km diameter
[ Maximum baselines will be at least 3,000 km from array core.

 

From

 

https://www.skateles...rochure_web.pdf

 

A quick back of envelope check suggests detecting radar at 200lyr is not unreasonable. The specified sensitivity is 400 micro Janskys (A Jansky is 10^-26 W/m2)

 

 

A  1MW 5 degree wide beam for example could give that at 200lyrs

 

Of course this is not the prime purpose of the SKA

 

Robin

Very good! And can't blame them for projecting their goal and the very limit of it's eventual, theoretical capability limit. What remains is further infrastructure: to overcome technical and funding hurdles ... or not. Either way, it's reasonable Press-Release Marketing. No complaints here. We will also >>>

 

>cure cancer

>stop the ageing process

>colonize the moon

>terraform Mars

 

So, completing this antenna seems pretty doable, in context!    Tom



#8 caballerodiez91

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Posted 18 November 2019 - 08:32 AM

I'm no radar expert, but I find it hard to believe it could pick up such faint signals from so far away.  I can't say that it can't, but it seems too easy.  I hope I'm wrong, and it can, though!  Any experts on the topic care to chime in?

From the study I deduce that it can as long as they use radars with the same or more power than ours.

 

If they use less powerful radars, we might still be able to pick up signals from a nearby exoplanet. 

 

I wish the SKA project was easy, but I'm afraid is not. It has been 30 years of preparation, 13 governments involved and 2 billion dollars of budget.


Edited by caballerodiez91, 18 November 2019 - 08:35 AM.



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