Every time I tap to change RC home position I get "Warning: The mobile device's GPS signal is weak and its location cannot be acquired"
This is not always true as I can see on the map the new home point location.  So it is confusing to know when it is true or not.

Apart of that I had an incident where the RC (iPad mini 2 Cell) GPS had lost satellites signal while performing a Follow Me mission in an open area.
As I could see in the recorded data it was a short warning but I didn't see it during the mission. I am not permanently watching the screen, the quad has also to be watched so I suggest DJI app to keep these warnings until the user taps to close them.

Anyway I purchased an external Bluetooth GPS XGPS150A and paired it with the iPad mini 2.
This Dual GPS has an app that displays connected satellites and the position confidence is good/excellent
But I still am getting "Warning: The mobile device's GPS signal is weak and its location cannot be acquired"

What can I do

Better location.  Also, does your external unit receive Glonass?

ag0n Posted at 2015-10-8 00:40
Better location.  Also, does your external unit receive Glonass?

Glonass, no

ag0n Posted at 2015-10-8 00:40
Better location.  Also, does your external unit receive Glonass?

Glonass, no

The GPS is in the Phantom. The satellites that you are seeing are the ones that the Phantom itself is receiving. try using the Phantom in a large open area. See if the signals and number of satellites increases. If it does, you have found your answer. Have you made any modifications to the Phantom itsel that would shield the Phantom receiver?

rodger Posted at 2015-10-8 10:27
The GPS is in the Phantom. The satellites that you are seeing are the ones that the Phantom itself i ...

You are talking about another GPS.  I don't have problems with the aircraft's one.
This is the RC's. It hasn't a GPS, it is the tablet/smartphone what gets RC location data.
If you are still there's no need to worry, aircraft and RC usually are almost at the same position.
But when the quad is in the air and you+RC are moving then you would like to change your home position.
You have two options: present aircraft location or yours+RC.
I am referring to RC position

marciano Posted at 2015-10-8 11:48
You are talking about another GPS.  I don't have problems with the aircraft's one.
This is the RC' ...

OK, I thought you were talking about the Phantom itself. I believe the smartphone and tablet location data is via triangulating the cell tower locations. I don't think there is an actual GPS in either the smartphone or tablet. That would account for your issue if I am right? You may have a weak or no signal from the cell provider. Another thing that could be possible is that the smart device may be receiving the GPS signal from the GPS in the Phantom/ Maybe one of the DJI guys can clear this up for both of us?