Sam Gentle.com

SDR

I've been messing around with RTL-SDR lately, which is what led to the ATC feed you see above. I'm pretty impressed with how much you can get done with nothing but a $20 TV tuner and some software. As well as air traffic, I've had some fun moments being reminded that there's still a non-internet radio service, reading pager messages, and listening to the hilarious hijinks of taxi dispatchers.

There's some super serious signal processing stuff you can do using gnuradio, up to and including communicating with recently-resurrected space probes. But most of the software available seems geared for that kind of heavy duty signal processing, with not much in the way of resources for the casual spectrum-surfing enthusiast. The software above is CubicSDR, which is great, but currently limited to analogue FM/AM signals.

It occurs to me that this would be a great area to inflict some hybrid web development on. You could have a nice modular backend in a fast language like C or Go to do the signal processing, and feed that into a JS+HTML frontend. The modularity would make it easy to add new decoding components for things like digital radio, TV and so on, and the HTML frontend would make it easy to create and iterate on different ways to visualise the signals.

Plus, being web-compatible would give you a lot of cool internet things that are currently pretty difficult. For example, an integrated "what is this signal and how do I decode it" database, or Google Map of received location data. The last piece of the picture is that a sufficiently advanced web UI would solve the cross-platform division that's currently making my life more difficult than it needs to be.

I'm really excited about the potential of SDR. The software is currently just a little bit too awkward to be suitable for general use, but it's so close! Most of the individual components are there, it's just missing a bit of glue, sanding and polish.