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Android

GPS and Data

So I've seen an app or two that allows a user to login on a mobile device (Android or iOS) and it uses the phone GPS to transmit location. A user with a master account can login to a website and see that users location.

Here is my quandary, what if the phone doesn't have data?

I am wanting to find a way to have SAR (search and rescue) volunteers to be able to use their phone so they can be tracked when out on a search. The problem is that they may be in an area with limited or no cellular data coverage. Will it work with just GPS?

3 Answers

No. GPS is a one way communication.

For areas with no reception they typically use sat phones for emergency.

That is why the Fire trucks use radio instead of cell phone for forest fires.

Is it one way satellite to GPS or GPS to satellite? I've got to find a cheap way to track these guys out in the field. If that mean build it myself so be it.

GPS is just a radio beacon sent from satellite containing a time reference.

The GPS receiver just reads that beacon and calculates distance.

The GPS unit does not send anything back

Maybe I can find a way to use ARPS and display it overlaying google maps or topo maps as long as I can display call signs or something to differentiate between operators.

Short burst satelite data plan may be your only solution