Reviewing my last flight I noticed my GPS dropped, for about a second or less, twice during my last flight.  Found a number of pilots reporting this issue.  Anyone seen this.  Could be a serious issue.  

The last two flights i made, I had the exact same thing happen. As I was watching the aircraft and not the iPad Air,2 screen, I didn't notice it until I replayed the flight in the go app.

After doing a little more research and reviewing all of my flight logs, gps has never dropped during flight previous to updating to DJI Go 2.8.5 for iOS
Every flight since the app update has lost gps signal, going from 15-18 satellites to zero for a second, and then back to 15-18. Each time, the aircraft was between 630 and 680 feet away from the home position, at various locations, always flying away from home. Returns to home over the same route do not drop signal.
Odd.

It happened to me too (on my P4) a few days back with the current firmware/iOS/DJI Go - as you say, it was only for a second or so and I didn't notice it until I reviewed the flight log afterwards.

It happened to me to. I noticed that it happened when i took photos. It´s also happened once in midflight away from home. I thought it was something with my P4, so I have downgraded and upgraded the firmware. I also did a factory reset.  It´s not until i read this thread that i relized that the problem started when the app was upgraded. I use a Ipad Air 2.

Stop worrying, it is perfectly normal. GPS is like any other radio reception system, it is not constant nor is it perfect. It is also an incredibly complex system, trying to receive data from a large number of satellites. It is quite normal to lose signal momentarily, particularly if you make a sudden movement like a yaw that changes the psoition of the aircraft in the sky.

I can't see how an app running on a tablet of phone can affect the GPS receiver in the craft.  I'm wondering if the GPS receiver in the craft is actually losing contact with all GPS satellites briefly, or if the latest iteration of DJI-Go for iOS is misreading the data sent from the craft and erroneously logging zero satellites.   

I have several logs from the past couple of days on Healthy Drones and at no time do I see less than 10 satellites.   FWIW, this data was from Litchi flights and not DJI-Go.

If you lose all satellites while flying, you know it - even without looking at the screen. You get a pop up and the aircraft switches flight modes. None of my flights lost satellite during flight. It only appears to lose them during playback since the 2.8.5 app update.
And no Geebax, it's not normal to lose GPS signal completely in open air. Maybe in your country, but not here. Before the last app upgrade 30 hours of flight logs reviewed, no GPS signal losses. After the latest update, 1 hour flight log reviewed, 3 GPS complete signal losses. Am I worried? No. But don't try to blow smoke up my ass and tell me it's normal.

Hotolds442 Posted at 2016-7-31 09:46
If you lose all satellites while flying, you know it - even without looking at the screen. You get a ...

What do you mean 'in my country'? It is no different here to anywhere else. Yes, you can have loss of GPS lock, it happens all the time, and usually only lasts a second or so. Especially when flying in cities or around tall buildings. It even happens in open air when the rotational position of the aircraft changes.

'blow smoke up your ass'? No thanks. I looked your arse up on the Internet and it is butt ugly.

Hotolds442 Posted at 2016-7-31 09:46
If you lose all satellites while flying, you know it - even without looking at the screen. You get a ...

The G in GPS stands for Global and GPS works the same way everywhere.
How are you reviewing the flight data to check?
The app is known to occasionally give false alarms.
If you go to http://www.phantomhelp.com/LogViewer/Upload/
Follow the instructions to upload your flight record.
You can see your actual flight data with flight info recorded every 1/10th of a second and see if you really lost GPS or if it was just an app false alarm.

Geebax Posted at 2016-7-31 06:42
Stop worrying, it is perfectly normal. GPS is like any other radio reception system, it is not const ...

geebax:
I think you have no idea how how works. There is no large number of data.that's the trick.And there is never a drop of that send data at all. Even if.you need only 3 satellit for a position. But we use up to 12. If a satellit fails, there is a lot redundancy. If American system fails, the drone is even using glonas.
Its a hardware error or a software error of the drone.
Regards
Captain T.Reimann

If we have GPS errors on board, after new software, most of the time someone forgot to set up correctly the baud-rate to 4800 between GPS antenna and computer.
That brings data collision  in the bus.with that it can happen that some part of the NMEA string goes lost.

thorsten.yachtc Posted at 2016-7-31 13:11
geebax:
I think you have no idea how how works. There is no large number of data.that's the trick ...

Yes, I have a very good idea of how GPS works, I have been using GPS systems for many years. I have built and sold entertainment and announcement systems for use in planes and trains. And we are not talking about how many satellites are seen, it is about whether the GPS receiver has lock on sufficient stallites to obtain a positional fix. And that can be interrupted for brief amounts of time. Like almost all the messages in the DJI system, they are cryptic and do not necessarily reflect what is going on. And what the hell is the Captain bit, am I supposed to be impressed by that?

Geebax Posted at 2016-7-31 11:46
Yes, I have a very good idea of how GPS works, I have been using GPS systems for many years. I have ...

Sir,
If you have no copy what a Captain is, feel free to shoot out.  But if your small tiny life is in my hands during voyage, May u respect the is more.Feel free to be impolite here..
Dosent make you to an expert to know  how a satellit sends positions or what they send at all. U are a user backend. Bit data..LOL

thorsten.yachtc Posted at 2016-7-31 14:13
Sir,
If you have no copy what a Captain is, feel free to shoot out.  But if your small tiny life  ...

My what a lot of assumptions. A captain does not necessarily have a clue about radio systems and how they work, but unlike you, I am not going to insult you by making the same sort of accusations you are.

I do happen to know about GPS systems and it is very likely I have been using them longer than you have even known about them. My background is in electronics and I was using Marconi GPS receiver sub-systems from the time they first became available.

Lets just leave it at that before I take you up on your invitation to be impolite.

This happened to me. I got compass error, lost gps briefly and had a flyaway. Was able to recover it as loss of control only lasted a few seconds. Scary as hell though

Michael M Posted at 2016-7-31 14:25
This happened to me. I got compass error, lost gps briefly and had a flyaway. Was able to recover it ...

Then you actually lost GPS positioning if you lost control and had a fly-away.
Mine has only reported it during playback. Onboard flight data sees no such loss.

Hotolds442 Posted at 2016-7-31 16:44
Then you actually lost GPS positioning if you lost control and had a fly-away.
Mine has only repor ...

As Labroides suggested, it would be good to upload your flight record to Phantomhelp, then we will be able to see what is contained in it. It seems very odd that there is a loss of GPS signal only showing up in the replay, and not at flight time.

Michael M Posted at 2016-7-31 16:25
This happened to me. I got compass error, lost gps briefly and had a flyaway. Was able to recover it ...

That doesn't sound like a flyaway at all.
It very much sounds like you had a compass error and your Phantom switched to atti because it was unable to deal with conflicting data and you were disoriented.
Looking at the flight data would show exactly what happened if you are interested to know.
A Phantom that loses horizontal positioning because it is in atti and is subject to drift is a very different thing from a Phantom that says bye-bye and shoots off somewhere you don't send it.

Michael M Posted at 2016-7-31 02:25
This happened to me. I got compass error, lost gps briefly and had a flyaway. Was able to recover it ...

Like #19 said, your case is different. It's because of the compass error, the drone switched to A mode and stopped using the GPS signal.

Before I report this to R&D team, I just want to know, has anyone experienced this in Android device or  iOS versions earlier than 2.8.5 ?  

+1  This happened to me twice during flight yesterday.
IOS.

Tobbe7305 Posted at 2016-7-30 18:32
It happened to me to. I noticed that it happened when i took photos. It´s also happened once in mid ...

Did you see it when you were flying? Or in playback like other people?

DJI-H.C Posted at 2016-7-31 18:35
Did you see it when you were flying? Or in playback like other people?

Same happened to me today. The GPS message didn't come up while flying, but the craft reported that it didn't have enough battery to return home and began the RTH countdown.
I thought I had a battery issue until I replayed the flight in DJI GO and saw the GPS disconnect mid flight. The craft thought it was 15,850km away.
It disconnected again as I was hovering and running the battery to 10%

This is not good, never happened before the latest update to GO.
I also had some twitchiness and hover instability. Windless day.

DJI-H.C Posted at 2016-7-31 12:35
Did you see it when you were flying? Or in playback like other people?

I only saw it in playback mode..

DJI-H.C Posted at 2016-7-31 12:35
Did you see it when you were flying? Or in playback like other people?

I only saw it in playback.

DJI-H.C Posted at 2016-7-31 11:31
Before I report this to R&D team, I just want to know, has anyone experienced this in Android device ...

I can confirm I have not seen this happen on versions earlier than 2.8.5 on iOS - when it did happen whilst reviewing the flight logs that day, it was the first time I had seen this message and I wasn't quite sure if it was referring the Phantom's own GPS or the iPad's at the time nor what triggered it. It was shortly after that it dawned on me it was part of the flight log.

The last flight I did: https://healthydrones.com/main?f ... ;page_id=SENSORSGPS
Notice there's no GPS abnormalities.
At 07:20 minutes satellites drop to zero in the DJI Go flight review. At 11:36, it drops to zero again.
Onboard GPS signal was excellent during those times as reported by the flight log.
This flight was the second flight on the battery charge, so the clock starts at 06:34.
As I stated earlier, this issue only appeared after update to iOS  2.8.5, and has occurred on every flight since the update. At no time did I suspect that the actual GPS signal was lost at the aircraft since it never tried to switch to Atti or gave a popup message.
I tried to upload the log to phantomhelp.com as lab rat suggested, but after 1/2 hour all I had was a blank data screen with column headers.
If you need more info HC, let me know.

labroides@yahoo Posted at 2016-7-31 15:55
That doesn't sound like a flyaway at all.
It very much sounds like you had a compass error and your ...

I read iver the flight logs, im an experienced user.
I did briefly loose control but regained it a few seconds later. It was stuck going full throttle at 20m/s until i was able take over abd slow ut down. Oh well lesson learned, calibrate your compass extra cautiously and slowly.

Michael M Posted at 2016-8-1 08:36
I read iver the flight logs, im an experienced user.
I did briefly loose control but regained it  ...

Goong to also calibrate my controller.

OP: I will set up a poll on the thread and see who else is having these issues. Ill post a link when its set up.

I finally got some flight logs uploaded to phantomhelp.com. All of the flight logs that were recorded after the 2.8.5 update show the same abnormalities as the data contained in this thread :http://forum.dji.com/thread-59702-1-3.html
Flight logs recorded before the update appear normal.

There are definitely some bugs in the 2.8.5 app.

This is the same flight from post #28, and how phantomhelp.com has interpreted the data: http://www.phantomhelp.com/LogViewer/I21MFW98DEVCDLTYZBIQ/