Guide to Doing Radio Astronomy with RPi and SDR [pdf](drive.google.com)
drive.google.com
Guide to Doing Radio Astronomy with RPi and SDR [pdf]
https://drive.google.com/file/d/1ssS_zBQWDEXMENc2_aqqPGxGkEEU5Ea3/view
24 comments
Software defined radio is a lot of fun for me, there is interesting math, there are weird RF signals to investigate, and it is fun to decode things like ADSB flight data. That said, if you want to do real science, you can also do radio astronomy with these things. For a relatively small amount of money ($300 - $500 US) you can set up a radio telescope in your back yard that doesn't suffer from a lack of "dark sky". Also makes for a great science project!
And they can help us out witn SatNOGS (https://satnogs.org) as soon as they finish this up now that they are familiar with Raspberry Pi and SDRs ;)
That’s interesting, but, given the network, what do you do with it?
So Low Earth Orbit satellites pass overhead you just a few times over the day and you have like a few minutes to actually receive the data they transmit. For especially for experimental cubesat missions of University teams etc that can be problematic.
With a network with many ground-stations all over the world people assist teams by coordinating receiving these signals. We all share it in a common database and these data is available to everyoneone (mostly researchers).
It's something that I consider fun and interesting while on the same time facilitates researchers (not all people share the same definition of fun with me).
Disclaimer: I've been part of this community since it started so I'm certainly biased
With a network with many ground-stations all over the world people assist teams by coordinating receiving these signals. We all share it in a common database and these data is available to everyoneone (mostly researchers).
It's something that I consider fun and interesting while on the same time facilitates researchers (not all people share the same definition of fun with me).
Disclaimer: I've been part of this community since it started so I'm certainly biased
Actually I am really interested joining! Alas there is the 5 days rule: "If you want to begin sth, do not delay too much, else..." and I currently have some pile of tobedone-things and it should not grow but shrink :) Still, some "reading and pre-probing" should be possible. Luckily in this thread you linked some initial reading for this...
Do you have any particular references for backyard radio astronomy? I have been thinking about a visible light observatory, but those have a lot of constraints. So I was curious what could be done with a backyard SDR setup.
I've had a lot of fun doing Hydrogen line backyard astronomy. I wrote up an article on my experience [1]. These are two great sites as well [2][3].
[1]https://hmcguinn.com/posts/hydrogen-line/ [2]https://www.rtl-sdr.com/cheap-and-easy-hydrogen-line-radio-a... [3]https://physicsopenlab.org/2020/09/08/milky-way-structure-de...
[1]https://hmcguinn.com/posts/hydrogen-line/ [2]https://www.rtl-sdr.com/cheap-and-easy-hydrogen-line-radio-a... [3]https://physicsopenlab.org/2020/09/08/milky-way-structure-de...
Very nice writeup! Getting into SDR is an eye opening experience. A little stub of conducting wire lets you tap into a dimension that is completely invisible to our senses. It's almost like hearing there are billions of neutrinos passing through your thumbnail every second, except there are people and machines on the other end.
There's a huge list of things you can do with the RTL-based SDRs in the article. Expanding to more capable hardware generally improves the quality of the data and enables higher bandwidth use cases that are difficult to pull off with cheaper radios, but for $30 you can get into all sorts of interesting stuff. (Turns out making your own antennas is half the fun)
If you want to just poke about you can access SDRs online through web-based consoles like websdr.org and kiwisdr.com (mostly shortwave and ham bands, the latter has a cool trilateration feature) or some of the major SDR software products (like SDR-Console and SDRSharp) have their own volunteer network of radios you can tune into (with caveats and limits of course) with their software.
There's a huge list of things you can do with the RTL-based SDRs in the article. Expanding to more capable hardware generally improves the quality of the data and enables higher bandwidth use cases that are difficult to pull off with cheaper radios, but for $30 you can get into all sorts of interesting stuff. (Turns out making your own antennas is half the fun)
If you want to just poke about you can access SDRs online through web-based consoles like websdr.org and kiwisdr.com (mostly shortwave and ham bands, the latter has a cool trilateration feature) or some of the major SDR software products (like SDR-Console and SDRSharp) have their own volunteer network of radios you can tune into (with caveats and limits of course) with their software.
I recently just discovered how radio is everywhere in our lives and I wanted to experiment and learn it. but as I dove deeper I learned that its illegal to emit your own radiowave. so I gave up cause I'm scared to do something illegal unknowingly but it succs because I really wanted to learn how nasa talks to mars rovers with radio by getting by getting my hands dirty.
Fear be gone!
I took the plunge got the license started learning radio. turns out everything I have wanted to do so far which is listen and learn I never needed the license for in the first place.
The amateur license is to transmit.
You can receive anything anytime anywhere in fact you are anyway since we are continually bathed in an electromagnetic soup you may as well decode bits of it.
Software Defined Radio (SDR) dramatically lowers the barrier to seeing chunky bits in this electromagnetic soup.
I first got a rtl-sdr (usb dongle) for under $10.
Now I am having a blast building Quadrifilar Helical Antennas from plumbing supplies to get the pictures NOAA satellites are sending when they are over head. (no license needed)
I encourage anyone with even a passing interest to to consider starting with "read only" and not even worry about talking the transmitting tests till you figure out if that what you want.
I took the plunge got the license started learning radio. turns out everything I have wanted to do so far which is listen and learn I never needed the license for in the first place.
The amateur license is to transmit.
You can receive anything anytime anywhere in fact you are anyway since we are continually bathed in an electromagnetic soup you may as well decode bits of it.
Software Defined Radio (SDR) dramatically lowers the barrier to seeing chunky bits in this electromagnetic soup.
I first got a rtl-sdr (usb dongle) for under $10.
Now I am having a blast building Quadrifilar Helical Antennas from plumbing supplies to get the pictures NOAA satellites are sending when they are over head. (no license needed)
I encourage anyone with even a passing interest to to consider starting with "read only" and not even worry about talking the transmitting tests till you figure out if that what you want.
thank you so much! ill get back learning radio again!
I encourage you to learn more. There are frequencies where anyone can transmit small amounts of power (they are the unlicensed bands) and they are available in every country. Many countries also have an amateur radio organization which are people like you who are interested in radio and want to learn more. Opportunities are available to use your radio to assist in disasters and other emergency situations, and of course it can lead to a career in working with a commercial broadcasting company.
thank you so much for the encouragement! ill get back to learning radio! so interesting
Get into amateur radio, then get a license basically you just need to know what the limits are.
https://en.wikipedia.org/wiki/Amateur_radio
https://en.wikipedia.org/wiki/Amateur_radio
Great project!
I am surprised to see the actual "telescope" being a metal pipe with a small funnel - there is no satelite-DISH-reciever-thing ! I have to dig deeper... one day...
Btw I was hesitating to fetch the pdf, because I had to allow javascript for both google and gstatic on my computer, which I normally would not do. Why is it, that following a link to a google drive file needs this local execution of code stuff instead of simply delivering the file? For public openly accessible stuff this feels very weird to me ( comparing to simple (s)ftp file fetching)
Btw I was hesitating to fetch the pdf, because I had to allow javascript for both google and gstatic on my computer, which I normally would not do. Why is it, that following a link to a google drive file needs this local execution of code stuff instead of simply delivering the file? For public openly accessible stuff this feels very weird to me ( comparing to simple (s)ftp file fetching)
This is off-topic and not a criticism, my apologies if it is not well received. I am not sure if I worded this correctly.
It helps to have some kind of introduction if we want to share our work with a wider audience. For this kind of topic I think that the people who already know what radio telescopes and radio astronomy are would be able to find this kind of information elsewhere if they wanted, but people like me who don't are "scared away" by the information because there is no introduction to the topic.
It helps to have some kind of introduction if we want to share our work with a wider audience. For this kind of topic I think that the people who already know what radio telescopes and radio astronomy are would be able to find this kind of information elsewhere if they wanted, but people like me who don't are "scared away" by the information because there is no introduction to the topic.
>The goal of this project is to enable everyone to discover that our Milky Way Galaxy surrounds
us
The quote is from the purpose on the first page. All of it really is at a DIY level were you get enough information to actually do something, but you will still hit snags. So you might be right that it is not aimed people who do not know the basics. I do not see the weakness in the writing so maybe you could explain what you would need?
The quote is from the purpose on the first page. All of it really is at a DIY level were you get enough information to actually do something, but you will still hit snags. So you might be right that it is not aimed people who do not know the basics. I do not see the weakness in the writing so maybe you could explain what you would need?
I can chime in regarding some weaknesses of the linked document.
I approach this as a highly technical person, programmer, electronics tinkerer, and someone who has been actively exploring SDR for over a year now, with RPis and a few different SDR hardware and software types.
I've become quite familiar with how "terrestrial" radio works from this period of experimentation, and I think most people who have ever used any form of analogue radio would not have much issue figuring out what's going on just by playing with an SDR and a length of wire as an antenna.
I opened this document expecting some introduction as to how I might get started with radio astronomy. After reading the whole thing through, I'm left rather in the dark about what results I would be seeing if I were to go to the trouble of following the instructions and getting it running;
- the document in parts seems to be a bit back to front. some of the concepts are explained after the instructions to implement them
- it's full of technical jargon which is not explained at all
- it doesn't explain how to interpret any of the captured data beyond "this small bump represents the milky way" - what else, for example could be observed with this equipment, and how does that differ from what's shown?
- it offers no help as to how to figure out what's going on if your results don't match what's shown in the document
- it offers no indication of where to go after carrying out just the one observation shown
- there's clearly some text missing in the part about the analyse scripts and what they are supposed to do
I could go on, but the above would be my main gripes with it; the result of which has left me with a feeling that this has taught me nothing about radio astronomy and no desire to build the antenna or use the software.
EDIT: formatting
I approach this as a highly technical person, programmer, electronics tinkerer, and someone who has been actively exploring SDR for over a year now, with RPis and a few different SDR hardware and software types.
I've become quite familiar with how "terrestrial" radio works from this period of experimentation, and I think most people who have ever used any form of analogue radio would not have much issue figuring out what's going on just by playing with an SDR and a length of wire as an antenna.
I opened this document expecting some introduction as to how I might get started with radio astronomy. After reading the whole thing through, I'm left rather in the dark about what results I would be seeing if I were to go to the trouble of following the instructions and getting it running;
- the document in parts seems to be a bit back to front. some of the concepts are explained after the instructions to implement them
- it's full of technical jargon which is not explained at all
- it doesn't explain how to interpret any of the captured data beyond "this small bump represents the milky way" - what else, for example could be observed with this equipment, and how does that differ from what's shown?
- it offers no help as to how to figure out what's going on if your results don't match what's shown in the document
- it offers no indication of where to go after carrying out just the one observation shown
- there's clearly some text missing in the part about the analyse scripts and what they are supposed to do
I could go on, but the above would be my main gripes with it; the result of which has left me with a feeling that this has taught me nothing about radio astronomy and no desire to build the antenna or use the software.
EDIT: formatting
Thank you! For me this was enough to ignite an interest in seeing the Milky Way, with what seems like a weekend or two of work or ordering parts. Where to to after this is a very good question, but a friend who bought one of the better rx/tx SDR units tells me there is always some thing new to do in that land.
Following a bit of a trail from a link in the doc I've found a whole bunch of related technical docs:
- https://github.com/WVURAIL/lightwork
- https://github.com/WVURAIL/lightwork
What a fun project. I love SDR.
Could you upgrade that to make a 2D picture? Would you need motors to step it around the sky?
Could you upgrade that to make a 2D picture? Would you need motors to step it around the sky?
Name the project "SETI@PI"?