Idiots guide to Radio Astronomy?

[Alan White]

Where can I find a true Idiots guide to Radio Astronomy?

I belong to the BAA and have looked at this resource as well as on this forum.
I am looking as a real technophobe and with no radio knowledge at present.
 

It needs to be very simples like me so I can understand the basics.

Edited July 25, 2019 by Alan White

[vlaiv]

How simple does it need to be?

Quick search gave this, and it looks like fairly basic level:

http://www.radio-astronomy.org/pdf/sara-beginner-booklet.pdf

I'm no expert in Radio Astronomy (far from it), but it is interesting topic, and I've done some research (and thinking about it) myself, so I could possibly be able to answer some basic questions.

[Alan White]

Thank You @vlaiv

It needs to be really simple to start.
Simpler  or perhaps less wordy than the link you posted.

I find longer more technical articles offputting to read and glaze over by the third page.
Perhaps this route might not be for me?
 

 

[vlaiv]

Do you just plan to get basic understanding on the matter, or are you interested in doing some radio astronomy?

Radio astronomy is one of those fields of astronomy that you can't simply have "hands on" approach like observing. You need at least some level of technical background to be able to understand what you are doing. Results of radio observations are often just measurements of sorts - graphs and charts, rather than anything you can instantly see or take a photo of.

You can produce images, but it is rather complicated, and as amateur with any sort of gear that amateur can house and operate - it will be very low resolution type of the image, so you can in principle only do "wide field" images - like that of Milky way.

[Alan White]

I am very much a hands on astronomer Vlaiv.
I take note of your information.
Perhaps something like meteor detection that has a well trodden path would make the most sense?

[vlaiv]

In that PDF that I linked, there are couple of projects that are worth looking up to see what is involved.

One of them is meteor detection. Another interesting one can be Itty-Bitty radio Telescope (IBT) - that one is just satellite dish and receiver (satellite detector).

Maybe that second one could be interesting starting point as you can "upgrade" it bit by bit. It is just a dish connected to satellite detector - one that "beeps" when you have a signal. So you point dish to something and detector beeps - you have a detection of a radio source! Most often you start by finding Sun this way.

Possible upgrade paths would be - mounting dish on EQ mount so you can use handset or computer to point it to wanted location. Another one would be connecting satellite detector to computer via some sort of sampling device - like simple external (USB) audio card that can sample input, so instead of listening to "beep" of detector - you record it via computer.

Look here for resources:

https://opensourceradiotelescopes.org/itty-bitty-radio-telescope/

[Coto]

Hi Alan,

 

Your concerns are exactly the reason I built PICTOR. Quoting from my previous post,

PICTOR is an open-source radio telescope that allows anyone to observe the radio sky using its convenient web platform for free. The goal of this effort is to introduce students, educators, astronomers and others to the majesty of the radio sky, promoting radio astronomy education, without the need of building a large and expensive radio telescope by the user.

PICTOR consists of a 1.5-meter parabolic antenna that allows anyone to make continuous and spectral (i.e. hydrogen line) drift-scan observations of the radio sky in the 1300~1700 MHz regime for free.

For more information, please take a look at the Website: https://www.pictortelescope.com/, the GitHub repository: https://github.com/0xCoto/PICTOR and/or the PDF guide that includes some introductory information on radio astronomy as well as instructions on how to use the telescope: https://pictortelescope.com/Observing_the_radio_sky_with_PICTOR.pdf

 

This way you will be able to observe the radio sky without having to really worry about lack of knowledge in the field. I will try to shorten the PDF Guide a bit (10 pages might be too much stuff to read through for most people I believe) and change a few things up a bit, but it includes some introductory radio astronomy information and instructions on how to use PICTOR (slightly un-updated but sufficient for the most part). If you don't have the time to read the whole PDF I'd suggest you at least take a look at the resources, it has two interesting short YouTube videos that should give you an idea of what radio astronomy is about. Ideally (for me) if you have something like Discord (see my signature) I'd be more than happy to help you there with absolutely anything you need (I suggest Discord because it is a more direct and efficient way of communicating in my opinion).

[Alan White]

@Coto Thank you, very interesting indeed.
I will have a proper read and look over the weekend.

[StarryEyed]

Alan.

Radio is an interesting area of astronomy. Particulary given that it also can be used during the day. 

Valiv's link is for the Society of Amateur Radio Astronomers. So in there is Amature Radio. The Radio Society of Great Britain is responsible for us here in the UK. Also the British Astronomical Association has a radio section.  All of these have nice sections. 

A good starting project is lightning detection here on earth usung a radio. You can tune in anytime! This is useful so you can identify it later as something earth originated.

Plenty to play with if you have a SDRplay your ready to go.

Good luck.

Kevin

Call sign MOLKJ.

😉

Edited July 28, 2019 by StarryEyed

[StarryEyed]

Oh and with the perseids in august look up meteor scatter french transmitter. There was a great article on it in the RSGB magazine Radcom earlier this year. Britastro has some great pdfs

https://www.britastro.org/radio/projects/Detection_of_meteors_by_RADAR.pdf

Did you know amature radio guys bounce radio waves of meteor tails to talk to each other!

Really a radio should be on even if its cloudy.

Edited July 28, 2019 by StarryEyed

[Alan White]

@StarryEyed thank you, that is more along the lines of what I am initially thinking of 

As a teenager I was lucky enough to be given a SW Radio from a Lancaster Bomber from a radio enthusiast,
I had many happy hours sat with headphones on listening in. It went onto another friend who has had a career in Broadcasting.

I went on to have a CB radio, which was perhaps a step down, but got me broadcasting (talking rubbish) each night and again great fun.

Meteor detection using radio kit sounds a great way to start, thanks for the link.

[Tomatobro]

Take a look at http://www.livemeteors.com/

This is a live meteor detection website. Based in (I think) North America/Canada. It gives you an idea of what meteor detection is like when using the GRAVES transmitter in France

[Alan White]

18 hours ago, Tomatobro said:

Take a look at http://www.livemeteors.com/

This is a live meteor detection website. Based in (I think) North America/Canada. It gives you an idea of what meteor detection is like when using the GRAVES transmitter in France

That was interesting to read, listen to and watch.
Very interesting indeed.
Looks a cheap way into radio interests, obviously a money pit once the door is opened of course!! 😂

[Tomatobro]

Its not too expensive to build a basic setup. My first yagi antenna was built using copper water pipe and a wooden frame. For a receiver I would strongly recommend a decent SDR (Software Defined Receiver) such as the Funcube Dongle Pro Plus. The cheapo versions of SDR's just don't work.

The Funcubes sometimes come up for sale on the auction websites.

[BiggarDigger]

15 hours ago, Tomatobro said:

Its not too expensive to build a basic setup. My first yagi antenna was built using copper water pipe and a wooden frame. For a receiver I would strongly recommend a decent SDR (Software Defined Receiver) such as the Funcube Dongle Pro Plus. The cheapo versions of SDR's just don't work.

The Funcubes sometimes come up for sale on the auction websites.

Less expensive SDR's work just as well for meteor detection.  This is the SDR I use: https://www.ebay.co.uk/itm/202297427602 currently selling at less than £20.

It doesn't match the specification of the Funcube, so may be less flexible to use for other purposes, but as a dedicated meteor detector, it's great.

Richard

[Alan White]

What Yagi would I need if I don't make it?
Any links please 😘

[BiggarDigger]

3 hours ago, Alan White said:

What Yagi would I need if I don't make it?
Any links please 😘

That's less easy to answer as a lot depends on your location, immediate topography, ground clutter and mounting arrangements (whether inside or outside for example).

Since you're in South Essex, it's reasonable to assume you would want either to slightly elevate the antenna, or to have a broad vertical beamwidth if attempting to receive signals from the GRAVES Radar.  That being the case, a small yagi would suffice and a quick search online shows plenty of options.  This 3 element https://www.radioworld.co.uk/sandpiper-2m---3-element-beam-antenna-5dbd will suffice if you have a clear view, or you may need higher gain by adding a couple of elements, deepening on your situation.

If you wanted to make the antenna yourself, there's plenty of diagrams to be found online and it really is as simple as a wooden pole a couple of wire coat hangers cut and bent to the right dimensions and a tuning capacitor.  Since you'll only be receiving, you don't need to worry about power coupling and high grade  components.

I use a 2 element phased array antenna; a so-called HB9-CV design.  This yields close to the same forward gain as a 3-element yagi but is physically smaller and easier to mount.  I have a pretty clear horizon and mount the antenna on the side of the house, clamped to an old Sky satellite dish mounting bracket.  I'm probably 500km further north than you though, so my common volume to the radar is very close to the horizon, whereas yours will be elevated somewhat.

Richard

[Geminids]

There is a design on the BAA Radio Astronomy Group site (unfortuntaely not actively maintained at the moment but still open) that I have built and works well.  It is designed specifically for GRAVES and a number of other people in that group use it.  It featured in a Sky at Night Article (BBC mag) 

http://www.britastro.org/radio/downloads/SkyAtNight/BBC_SatN_HOWTOOBSERVEMETEORS.pdf

There are other interetsing  radio meteor articles on their  pages still.

Edited August 2, 2019 by Geminids

[Tomatobro]

Just to confirm that cheapo SDR's DO NOT work as well as the higher spec versions. I have two that that have been given to me by club members that switched to the Funcube after poor results with the cheapo's.

[Werner Roland]

Totally agree on cheapo SDR's. They're ok to dip your feet into SDR's, but any serious continuous use such for recording is difficult at best. I have 3 of them, and the slightest glitch such as plugging in a headset into the computer can cause them to freeze. Or even just jiggling the USB cable. I switched to an RSP1A just for meteor logging, and it hasn't frozen up even once. Plus it produces much cleaner looking waterfalls. The extra bits really make a difference.

[BiggarDigger]

Well, what can I say?  Maybe I just got lucky using an inexpensive SDR, an inexpensive feeder and a simple small 2 element antenna from 1000km away from the radar?  However, I've recorded 910 meteor pings today and counting....

Let me clarify for a moment: The less expensive SDR's are definitely not a match for the performance of the Funcube or other high end SDR's.  The differences compared to the high end devices include lower dynamic range, lower sensitivity, poorer frequency stability, smaller RF and IF bandwidths and less flexible interface.  These are measurable differences.

However, my SDR (the one I linked to above) has performed meteor detection admirably a full year, with the only loss of signal due to my own finger trouble, poorly implemented Windows updates and holidays.  Perhaps I miss a few scattered signals, but I have a limited common volume due to my range anyway.  Perhaps my peak signal to noise is not as high as it could be, but 50db SNR is pretty big on the larger returns.  Perhaps the device drifts a few Hz with diurnal variability, but a heatsink attached to the case adds to thermal stability.  Perhaps if I wanted to look at the Hydrogen line or Band II signals, I might need better RF bandwidth, but I'm content with the 143MHZ GRAVES Radar.

In summary, it's entirely possible there are cheap SDR's that are poorly built, poorly designed and poorly implemented, but I have had no issues with mine, save that the driver will not communicate with Spectrum Lab, but a free third party tool overcame that.

£20 for a toe in the water? Got to be worth a shot.  Then if the bug bites, or if higher performance is required, perhaps flog it on eBay and invest in a high performance device.

You pays you money and all that....

Richard

[Alan White]

Well I have gone for a 'Toe Dip' or Lucky Dip £18.95 SDR as recommended by @BiggarDigger and will build a aerial as per the S@N article. 

Limited outlay to see how I get on, if I like it or want more then better kit will be purchased.

Thanks all for the pointers, all much appreciated 👍


 

Edited August 2, 2019 by Alan White

[Werner Roland]

My computers are always updated, and server grade. No issues with maintaining those machines. The biggest problem for my dongles seems to be the USB-A connection to the USB cable. Handle that dongle and boom ... it freezes. Even pried the contacts outwards for firmer contact with a very fine screw driver, clean the contacts, and still happens. The USB-B connectors seems far less susceptible to handling live connections. Wish the cheaper dongles came with USB-B 😕

[Alan White]

Well progress has been made for this Idiot after a guide 😀

The Auzeuner  RTL SDR arrived while I was on holiday Progress point 1.
But then life (well a death) then got tangled in the way.

Yesterday sat down with the USB dongle and plugged in, downloaded the drivers and then nothing, didn't even show as a drive, darn it!
Look on the web and find its driver related, loaded some software and reset the USB driver, instantly found.
Progress point 2 

Have downloaded software to try running the dongle.
SDR Console v3, this worked and I can see and play with the dongle.
Progress point 3.

This may sound stupid to many, but I really have no idea what I am doing and each of these to me is a big step forward.

Off to the DIY shed when it opens to buy some pipe for the S@N Aerial build.
Hope to start on that later or tomorrow.

Keep you posted.......Graves Radio and Meteors, here I come!
 

[Geminids]

You are making good progress.  Keep in touch here.