Visualize Surrounding WiFi with the “World’s Derpiest Radio Telescope”

When you hear the term “radio telescope,” an image of a gigantic radio dome pointed at the sky likely comes to mind, allowing us to view the wonders of the cosmos. This is not that telescope. In fact, it’s small enough to be easily carried around by a single person and works in the 2.4 GHz range, the same frequency as WiFi routers.

As reported here, hacker Justin along with help from Paul at the Foulab Hackerspace in Montreal set up this little telescope to visualize nearby WiFi signals. It uses a pair of steppers to pan and tilt in space, taking readings and recording data under control of a laptop-based script. As seen at 3:30 in the first video below, a test at Foulab yielded the expected results, with a WiFi graph that can be perfectly overlaid with a visual image, yielding a bit blob ‘o WiFi right next to their server room. They even noticed a forgotten little router on a desk, as well as a WiFi blob from the neighbors.

They then took the device outside, and after much fiddling and Gigabytes upon Gigabytes of data, they were able to see what kind of signals were emanating from the surrounding buildings. It’s a very entertaining hack, and a concept that could have important applications for signal analysis.

Code for “Cogsworth: The World’s Derpiest Radio Telescope,” as it’s called in the overview video, is available on GitHub. You can also catch more detail on the construction process in the other two clips below.