Taking this from DJI post above:

In current iOS app, the home point is based on either RC's GPS or mobile device's GPS.
When RC's GPS signal is weak, the home point will based on your ipad's GPS, so it may lead to a moving point because of the less accuracy of mobile device's GPS.
It will be optimized in next iOS version.

As I understand that only iPads which have cellular capabilities have built in GPS units. The others rely on cross referencing Wi-Fi signals. I cannot comment on any android devices as I don’t use them.

So how does this work, if the iPad or equivalent doesn’t have GPS and what is the effect on the RC homepoint?
If as stated the RC’s GPS signal is weak how can an iPads be any better? Why is it then we are relying not on the purpose built device as in the Inspire but third part tablet devices?

Is it an iOS update or Inspire RC GPS that’s required? The only thing that's clear is Genettico demonstration selecting wifi, cellular, airplane mode further abnormalities seem to occur and his post stating

after the firmware update I cannot set dynamic  Homepoint to RC... Only to BIRD.

then the only reliable home point is the one we set with the craft after takeoff hovering at 4 feet.  Don't use dynamic home point till a new firmware fix arrives!!!   And don't stray to far from that recorded craft's home point!
agree?

Rockeyes Posted at 2015-4-20 22:08
Taking this from DJI post above:

I have tested as what you can see on video I provided. To not have the variable of issues with starting on one mode (i.e airplane and then switching it to WIFI) while flying, I have also tested on different modes without switching them mid-flight from a Turned OFF BIRD, REMOTE  and APP, to ON and FIXED on either, Airplane mode, WIFI (Network Around or not),WIFI OFF,  Cellular ON and OFF... and Have tried it on IOS and Android devices.

I cannot find anywhere on DJI's documentation (I.e manuals and Wiki) that we are to turn our mobiles devices to the Airplane mode when we are flying as many have been doing, There are mentions of interference while you calibrate compass and such, but I do see comments made by DJI members stating the Usage of the Mobile's device GPS signal to compliment the RC's GPS module.... and I can confirm that the reception as shown with  (blue or red) DOT on my videos indicate NOT flying on Airplane mode IS the best way to give a chance to the RC to acquire a better lock on GPS. If this indication is not accurate, then DJI needs to solve this and implement a solution but if it is displaying accurately and were to follow this we are NOT to fly on Airplane Mode, as it disables the GPS module on our devices.

Perhaps DJI should clarify this a bit more, and provide documentation for it.

in other word, link  the home point with the craft, not the remote!  dynamic linking with the RC is not reliable at present time until the next firmware release I guess

dentin11 Posted at 2015-4-20 23:16
then the only reliable home point is the one we set with the craft after takeoff hovering at 4 feet. ...

I just tested my 1s features after the new iOS and birds firmware upgrades blah blah ....   , it works fine !
Flew out 100 feet , walked 40 feet from my take off home lock and reset to the rc unit and then hit rth and it all works perfectly .. bird flew back and landed , did several auto take offs and landings etc all worked great ! Then it was beer 30...