Personal Locator Beacon
I've recently learned about PLBs and EPIRB, which basically send distress signals with position information from the device built-in GPS. They can be relatively expensive, so I'm wondering if anyone has made any work towards a home-brew device?
Legal Disclaimer: haha, homebrew is a poor term. These devices need to be registered etc., so it's not recommended ( and actually unsafe) to build your own device. What I'm looking for is education on how these things work and general pointers on how to approach the designing of such a device.