Meet Drone Shield, an Ambitious Idea For a $70 Drone Detection System

An anonymous reader writes "Here's an Interesting idea of how to use a Raspberry Pi and a few other inexpensive items to make a low cost detection system. From the article: 'The Drone Shield would combine a Raspberry Pi, a signal processor, a microphone, and analysis software to scan for specific audio signatures and compare them against what known drones sound like. (Because obviously a Predator drone is going to sound very different than a small quadcopter.) Once a match is found, the Drone Shield then sends an e-mail or SMS to its owner...'"

Range

[Dan East]

A Predator has an operating ceiling of 25,000 feet. You think a raspberry pi and mic is going to hear a Predator drone in cruise mode that's 5 miles above? You can't even hear a massive passenger jet at that altitude! Now a quadcopter is a different story, as they are as loud as can be, but saying this system would work on something like a Predator is a stretch.

Tough

[Cassini2]

It's tough to reliably detect low-level background repetitive noise without detecting all sorts of nearby domestic appliances, car engines, and such. In the modern city, we live with *alot* of noise.

Now, if the problem is to detect jet engines in rural areas featuring mountainous terrain, then I think I know what the point of this project is.

Re:Range

[multiben]

Just because you can't hear it doesn't mean a microphone can't pick it up. I am not going to google this because I am lazy, but I would not be surprised at all if a good quality, well aimed, highly directional mic could pick up enough of a noise to run an analysis.

Re:Interesting...

[BitZtream]

It is much more developed, you just don't realize it. This sort of signal processing is used in ultrasound machines, your car, my boat, fetal heartbeat monitors, little credit card readers that attach to your phone via headphone jacks. ALL SORTS OF STUFF.

Its all just an application of some FFTs and some weighting. It isn't even non-trivial for anyone with some basic understandings.

Without any prior knowledge, I went from no understanding to of FFTs to writing code to detect lean fuel during runtime on my R/C airplane. A Raspberry PI is also way more CPU power than needed to do it, which means it can also do a whole bunch of other stuff too.