Odd Software for Odd Jobs

raspberry pi

Project Idea: Lost Bushwalker Finder

I had this idea for a project that may be useful (or more likely useless). And it may or may not have already been done.

It requires a Raspberry Pi, a WiFi dongle, and a drone.

The idea assumes that the lost bushwalker has a smartphone with WiFi switched on but are out of mobile coverage (which is why they haven't called for help). I read somewhere that some (all?) smartphones with WiFi switched on are always looking for an Access Point (AP) to connect to.

I wondered if it might be possible to pinpoint, or at least narrow down, the location of the smartphone (and thus lost bushwalker) by flying a drone overhead in a search pattern with a open AP running so that any device can connect. The smartphone may see the AP flying overhead and thus try to connect to it.

The AP, a Raspberry Pi with WiFi, logs the attempt as well as the GPS coordinates and relays this back to the searcher.

It also assumes that, as it's out in the bush, there aren't many smartphones around. It also assumes that the searchers have WiFi on their phones switched off to avoid false-positives.

The WiFi dongle (or whatever) on the Raspberry Pi would need a boosted antenna to help pick up the weak signal from the bushwalker's phone.

Anyway, was just an idea. Might not be practical. But I thought it would be interesting to try out. And I would finally have a good reason to buy a drone!

Unfortunately, my family's been under the threat of forced-emigration for a while now. Makes it hard to concentrate on tinkering and inventing when your Aussie family may be forced to emigrate from Australia.