SRT: The Small Radio Telescope

The Small Radio Telescope (SRT) was developed by Haystack Observatory to serve as an educational tool for universities and colleges for teaching astronomy and radio technology.

The original SRT was popular, with several hundred being built and is still in use at many colleges. It is no longer available new, however, and advances in electronics have rendered the original obsolete. Development of a new SRT was undertaken by Haystack in 2012.

Small Radio Telescope (SRT)
Small Radio Telescope (SRT)

The primary philosophy of the latest design for the SRT is that the users should build the telescope themselves from commercially available equipment, based on plans, instructions, and software provided by Haystack. It is designed to be assembled easily with minimal need for special tools or skills. This approach provides an educational opportunity to the users who build the telescope. Also, users of the SRT will be more familiar with how it works if they assemble it themselves, allowing better in-house technical assistance.

The SRT is no longer available as a kit from Cassi Corp. If you decide to build an SRT, we recommend using the TV dongle version of the New SRT using parts list given at the bottom of this page.

The SRT wiki site

SRT Memo Series

SRT Assembly Information

SRT Software

We provide software, similar in appearance to the original SRT software but written in C instead of Java and running under Linux instead of Windows. Source code is available here:

SRT Reports


Ballard, S., R. Harris, L. Lanz, B. Maruca, and D. Muñoz, “Astronomy 218/Haystack project report,” Harvard University (2007) (pdf)

Salah, J. E.; Pratap, P.; Rogers, A. E. E. 2003, “The Educational Role of Small Telescopes in Radio Astronomy” The Future of Small Telescopes In The New Millennium. Volume II – The Telescopes We Use. Terry D. Oswalt, ed.; Astrophysics and Space Science Library, Volume 288, Dordrecht: Kluwer Academic Publishers, p.323-336

Pasachoff, J.M. 2002, ” Haystack radio telescope,” American Journal of Physics, 70(10):983


Oiler, J. K.; Rogers, A. E.; Oberoi, D., 2006, American Geophysical Union, Fall Meeting 2006, abstract #SH23A-0342, 2006AGUFMSH23A0342O (pdf)

Evarts, E. R.; Rogers, A. E. E.; Pratap, P. 2005, ” Using Small Radio Telescopes for VLBI-mode Interferometry”, American Astronomical Society, 2005AAS…207.6608E (pdf)

Johnson, W.; Pratap, P. 2005, “Classroom Experience with the Small Radio Telescope”, American Astronomical Society, 2005AAS…207.6503J

Vats, D.; Rogers, A. 2004, ” Development and Testing of a New SRT Receiver”, American Astronomical Society, 2004AAS…20515205V (pdf)

Gobeille, D. B. P., Rogers, A. E. E., Ball, J. A., Pratap, P. 2004, “Interferometry on the Sun using a Yagi-Uda Array and a Small Radio Telescope (SRT)”, American Astronomical Society, 2003AAS…203.1914G (pdf)

Altenhof, M., Berlin, D., Pratap, P., Erickson, P. 2002, “Solar and Geomagnetic Investigations: High School Astronomy Unit Focusing on the Sun/Earth Connection”, Bulletin of the American Astronomical Society, Vol. 34, p.1196

Whalley, D., Pratap, P., 2001 “Building and Using Small Radio Telescope at a Technical High School”, Bulletin of the American Astronomical Society, Vol. 34, p.560

Pratap, P., Ball, J. A., Rogers, A. E. E. 2001, &quotA Small Radio Telescope Interferometer at MIT Haystack Observatory”, Bulletin of the American Astronomical Society, Vol. 33, p.1342

Cobb, M. L., Pratap, P., Rogers, A. E. E. 2000, “A Small Radio Telescope for Education”, Bulletin of the American Astronomical Society, Vol. 32, p.1560

Kimball, L.; Pratap, P. 1998, “A Small Radio Telescope for Undergraduate Instruction”, Bulletin of the American Astronomical Society, Vol. 30, p.1294


Oiler, J., Rogers, A.E.E., 2007, “Analysis of Limb Brightening on the Quiet Sun at 21 CM Using a Three-Element Interferometer,” the MIT Haystack Observatory REU Program final report. (pdf)

Evarts, E. 2006, “Discovery of frequency-sweeping millisecond solar radio bursts near 1400 MHz with a small interferometer”, Physics Department Senior Honors Thesis, Brandeis University. (pdf)

Atiani, S. 2006, “Constructing a Radio Interferometer”, Physics Department, Guilford College. (pdf)