I recently damaged my P2V+ when the GPS dropped out unexpectedly.  I had to replace the body shells so I did the mod to my GPS.  That is, I re routed the GPS cable and put in extra shielding.
I am now much more observant with my satellite reception and since the modification I have noticed that there is no satellite drop when I turn on my camera.
However, I have just had a flight today and noticed something unusual.  I took off with 7 - 8 satellites but as soon as I rotated facing 90 deg in either direction it dropped to 5. When I returned to the original course it went straight back to 8 satellites.  This was consistent for the duration of the flight.
Has anyone else noticed this phenomenon with their phantoms or can anyone suggest what is going on with this?

What was your flying location and time and date of flight?

I was in a park where I normally test fly.  It is not the best location for satellites due to nearby hills.
The point I am making is that there was a big difference in the number of satellites that were locked depending on the direction the Phantom was facing.  This was totally consistent during the whole flight.
While hovering in a roughly northerly direction (I am in New Zealand - Southern Hemisphere) I was getting 8 satellites.
As soon as I rotated 90deg to the left, or the right, it would drop to 5 and go into ATTI mode.  If I turned back to the north I would get the 8 satellites again.
It didn't seem to matter what altitude I was at.  I also experimented by flying in Figure 8's.  As soon as it came around to the west and east quarter it would flip into ATTI, and then back into GPS in the North and South quarters.
I have checked on GPS Planner and it wasn't a good time for satellite reception, but I am puzzled why there would be such a difference depending on the direction the Phantom was facing.

Why does the Phantom need a minimum of 6 sats anyway ?  Please I know the obvious answer is 'because more sats mean better location' but I was always under the belief that you only needed 3 for an accurate position.

Yes. I've been wondering that myself.
Can anyone out there explain why 6 is the magic number?

umpa Posted at 2014-12-7 19:31
Why does the Phantom need a minimum of 6 sats anyway ?  Please I know the obvious answer is 'because ...

Using 3 satellites will give you a (2 dimension) position, (latitude and longitude) the same as a car gps unit.  In a (3 dimension) position, you are trying to find your position within a box.  Now you will need 6 satellites to give you the 3 dimension position. latitude, longitude and altitude.  It can be done with minimum of 4 satellites, but position of accuracy is not precise,  the more satellites you have, the better accuracy to within a couple of feet.  DJI programmed into the flight GPS a minimum of 6 for the accuracy.

alcampbell@xtra Posted at 2014-12-7 18:40
I was in a park where I normally test fly.  It is not the best location for satellites due to nearby ...

Hi Al, I am also in NZ- Dunedin, are you north or south island?

Hi Rod.
I am in Wellington.
Love my Phantom but not so happy with inconsistency with GPS.  I can fly it ok without GPS but when it flips from one to the other it makes it difficult.  It caught me out when it happened the first time and it was out of sight behind trees before I realised what was going on.  Resulted in it drifting off with the wind and crashing in thick bush.  Very lucky I was able to find it.

alcampbell@xtra Posted at 2014-12-8 05:53
Hi Rod.
I am in Wellington.
Love my Phantom but not so happy with inconsistency with GPS.  I can fly ...

Hi Al, windy welly eh?  It's a wonder you can fly at all! we have had it quite blustery here for the last couple of weeks- together with the rain of course- great flying conditions!  I have just switched to NAZA mode and tried the home lock function- it works well and I can see that being very useful.  I have had no problem with GPS and get between 8 and 10 sats usually Guess I'm lucky!

rod@voxvideopro Posted at 2014-12-8 12:57
Hi Al, windy welly eh?  It's a wonder you can fly at all! we have had it quite blustery here for t ...

Hey Rod.
Been really windy here but I just take the opportunities when I can and I am getting used to flying in windy and turbulent conditions.  That's why it concerns me when the GPS mode flips in and out.  I am happy enough flying in ATTI mode as I used to fly RC Helis back in the 90's, but it is quite a different feel between the two modes.
What are you mainly using your Phantom for?

I have experienced a fly away today after I rotated my drone by 90 degrees (I have posted a separate thread here).
Somebody said that there was a magnetic storm today - and I think the loss of GPS location was the cause of my fly-away.

I haven't paid too much attention at the number of GPS satellites during flight - but I have seen the drone lights going from green to yellow right before landing, so I assume something went wrong with GPS reception.

ciprianboboc@gm Posted at 2014-12-8 15:47
I have experienced a fly away today after I rotated my drone by 90 degrees (I have posted a separate ...

Interesting that you have had a similar event.  I flew my Phantom again today and I got a solid 10 satellites locked.  Rotated 360 deg and never dropped more than one satellite.  Direction drone was facing didn't make any difference and had  a great stable flight.  Maybe that magnetic storm had something to do with our unusual problem. Hopefully future flights will be as stable.

alcampbell@xtra Posted at 2014-12-8 14:40
Hey Rod.
Been really windy here but I just take the opportunities when I can and I am getting used ...

Hi Al, I have a company called Vox Video Productions  www.voxvideoproductions.co.nz  and I shoot mainly health and safety and induction videos for industry, with a few smaller marketing vids thrown in.  I bought the PV2+ to carry out some aerial shots for some training videos I am working on- open country and open water!
So it is another tool in the box for me. I do fly it for fun too, but mainly to make sure I know how to handle it!