There is no way that I can do anything more than the beacon until October 1st, but I would like to explain the whole project and its use cases.

It is simple: every active beacon (locator) appears on a map and anyone sees its current position. The beacon is mounted on the aircraft (be it multi-rotor, glider, powered RC model etc.). Scattered on the ground are several receivers, connected to the internet. When a receiver gets data from a locator, i sends it to a handling server that places the drone on a map. How is this useful ?

Let's consider our case: we test our UAVs near a utilitarian airfield ...

 There are lots of activities going on there: glider training and contests, private ULMs, recreational skydiving, acrobatics training and many more.

Before takeoff, we communicate our course to the airfield tower (handled by a single person) and he gives us the OK and announces all the others up there that we are joining them.

Fairly often, other aircraft arrive from far away, without knowing of our agreement with the airfield and cross our path. Most of the times, their altitude is greater than ours, but not always. Several times we were able to watch them from the onboard camera. And it is only pointed downwards...

If we place the locator on our UAV and a receiver (let's call it gateway) in the area (one is sufficient for a radius of several kilometers), it will give our position, altitude and speed. The traffic controller only has to open a web page with a map to see us in real time.

The same locator can be placed on a RC model or a multi-rotor. If it is close enough to the airfield to bee seen, it is probably too close, so it is much safer for everyone to know that someone is flying nearby. It doesn't have to uniquely identify you and your RC model, it only says "I'm also here!".

The local aircraft can also be fitted with the locator, and they will also appear on the map. Something like this. Only one airfield in Romania has a OGN receiver installed, but if you un-zoom, you probably won't see any glider on the map, because none is equipped with a transmitter. Here is a map with OGN receivers (and the only one in Romania).

And now we get to the second use case: the same hardware can be used for OGN network. RFM96 can also receive FSK modulated signals, used by OGN. Of course, that means a different firmware and it is just an idea for the moment.

The last use case is the emergency beacon. In case of a crash (determined with an accelerometer) different audio tones can be sent with different TX power and they can be received with a cheap 433MHz Baofeng hand held station. If the GPS receiver is damaged or it is unable to get a fix, audio signals might be able to narrow down the search. But this is too far away to consider right now, so let's get to work.