Arecibo. The Very Large Array (VLA) in New Mexico. The movie Contact. If you have any interest in space or astronomy, chances are you've heard about radio astronomy. But what is it?
Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. Radio astronomy is conducted using large radio antennas referred to as radio telescopes, that are either used singularly, or with multiple linked telescopes utilizing the techniques of radio interferometry and aperture synthesis. The use of interferometry allows radio astronomy to achieve high angular resolution, as the resolving power of an interferometer is set by the distance between its components, rather than the size of its components. (Wikipedia)
For the non-scientists out there, the short version is that everything that gives off energy has waves-whether it's above or below or on the visible spectrum of light. Radio waves have wavelengths billions of times longer than those of visible light, so radio telescopes give us a whole different picture of space than observational telescopes.
Go watch the movie Contact; I wanna be Jody Foster's character. But how do I get into radio astronomy without a PhD?
For me, the best place to start was learning about ham (amateur) radio. All the AARL licensing books cover the basics of radio signals. In my research for free study materials I not only found cheap and dirty DIY radio telescopes, but the Society of Amateur Radio Astronomers. They have a whole section on education, forums for other amateur radio astronomers to talk and share with each other, even a store where you can get a few small specialized radio telescopes for specific functions, like Sudden Ionospheric Disturbance (SID).
I'm not exactly going to get signals from extraterrestrials (yet), but at least learning about the various types of radio telescopes and what kind of data they produce will help me decide how I want to focus myself in this area.