Building a Radio Telescope : Part 1


A Project i've been putting off for quite a while is to try and build a Radio Telescope. I've been reading up about Radio Telescopes for about 2 years but i could never get my ass moving to start building one. And well, i've finally started working on one.

But firstly, let me tell you what Radio Astronomy is. The Wiki article is pretty detailed but basically, radio astronomy is observing the skies and studying the energy earth receives in the radio spectrum. I didnt say 'observing the night skies' because radio waves can be detected day or night, unlike in visible astronomy where the sun ruins the day time observations.

Listing out the process of Radio Astronomy -

  • Radio Sources - which emit energy in the radio spectrum.
  • Receivers - which are able to pick up these signals.
  • Data Analysis - for you to be able to infer something about the sources from this data. 

  • Radio Sources -

The emissions from Sun, Jupiter, The Galactic Disc and a couple of close by galaxies (Cassiopeia) basically form the strong radio sources when seen from earth. And there are different kinds of processes which are involved in these radio emission like Synchrotron radiation, Bremsstrahlung etc etc but that is for the more serious.


  • Receivers -

So, day or night, we receive emissions in the radio spectrum from different parts of the sky. And then comes detection. Any kind of antenna can be used to pick up these signals, even the basic Yagi Antenna or the now common Dish TV antenna receivers.And since there are emissions in different bands of the radio spectrum, you will almost always be able to pick up something.

The most easiest to build and operate is a Dipole Antenna, which are built to observe emissions of specific frequencies. One of the more popular, amateur dipole radio antenna which is being used for Radio Astronomy can be found here, it is a project funded by NASA and it is basically a Dipole Antenna designed to observe emissions specific to Jupiter, at the frequency of 20.1MHz. The link will give you further instructions about building the radio dipole, data analysis and further reading. And like i said, this is one of the more popular amateur receivers being used now a days for radio astronomy.


  • Data Analysis - 
So, now that we know what sources there are in the sky and we have an antenna to pick up their signals, we need to be able to decipher the signals these sources are sending to be able to understand something about them.

The frequency of the signals from these sources can be used to decipher how far away they are from us, the strength of the signal will tell us the amount of matter present at the source (which is causing the emissions) etc. You should read up the wiki article on Astronomical Spectroscopy to have a better idea on how to use this data.

I've tried to put it as simply as i could. But the next time, i am not going to hold back. Im going to go total nerd on you. I will write on what exactly i am trying to build, how i intend to record the signals from the antenna and process the data through MATLAB.

And last but not the least - you ask why i do this?
Because i wanna look at the stars in the day time as well, 8 hours in the night is not enough! :D
Until next time...

Popular posts from this blog

Arxiv author affiliations using Python

So, I wanted to get author affiliation information from papers on arXiv. arXiv provides with an API to bulk query their database and get information. Following that, I look for the attribute 'arxiv:affiliation' in the html data. Here's the code - import urllib from BeautifulSoup import BeautifulStoneSoup   url = 'http://export.arxiv.org/api/query?search_query=all:astro&start=0&max_results=1000'   data = urllib.urlopen(url).read() soup = BeautifulStoneSoup(data) #print(soup.prettify()) #list = soup.findAll('arxiv:affiliation') #for i in range(len(list)): #        print list[i].contents   test = [tag.string for tag in soup.findAll('arxiv:aiffiliation')] Now, the problem I'm having is that I'm getting affiliation of all authors which I want to split into sets of affiliations of authors of a paper, which I'm stuck on at the moment. Once I get that part, I can move on to the next part of this pet project, displaying these
Read more

Farewell to Enthought

I started my professional career at Enthought , at the Pune office in India, on Feb 29, 2016. Over the course of eight long years, I spent time at the Austin office in the US, the Cambridge office in the UK, and I worked remotely from India. I was let go on March 27, 2024 . I had an unbelievably great time. I had three amazing mentors - Pankaj Pandey, Senganal Thirunavukkarasu, and Mark Dickinson. Pankaj mentored me in my first year at Enthought. I started paying attention to the craft of software after working with him. Senganal started mentoring me in my second year at Enthought, and continues to mentor me, even after the both of us have moved on from Enthought. He instilled professionalism in me, ensuring that the code I wrote produced precise scientific results, and that I tackled the known unknown aspects of a project first, to ensure timely communication about project progress. I was eager to manage people at the time and Senganal made me realize that I didn't want to manage
Read more

Elementary (particle physics), my dear Watson

Ground Control to Major Tom:  Shruti Patel checking in. Since my dear friend and fellow-physicist Rahul Poruri is homeward bound, and shall remain there for a week, I'm stepping in to continue his tradition of daily posts to Astronut . Even as I write, I'm not quite sure what this post is going to be about, so please forgive me for occasional rants and digressions.  By the way Rahul, I totally resent you for the name of this blog- I'm never going to start my own blog because there's no way I'll come up with a name as cool as Astronut! For now, I shall try and be happy with being a guest writer! Before I begin, a little bit on who I am and what I do; so that you can trust that my general views on science- particle physics in particular- are not entirely baseless. I graduated with a masters in Physics from IIT Madras in July this year, and I'm currently working towards (an eventual) PhD with the Theory Group at the Deutsches Electronen-Synchrotron (DESY)
Read more