I've seen a lot of posts on this forum about Home Points being way off, and Drones just flying away to a new location.  The general consensus is that it is a DJI Firmware or Go App problem.  Well, that may be.  But let me tell you of a problem I'm having with GPS in general that sounds very much like the problem us done flyers are having.  In my work I use a smart phone with GPS navigation to locate my customers when I revieve a service call.  It is part of our program.  I get an address, and then a Radio Button that says "Map".  I select map and it takes me to Google maps and plans my route by the shortest way.  We have used it for years now without problems.

But in the last few months I have noticed errors in location by as much as 10 miles.  Generally it is only about 1 mile off.  Twice in the last week I have been directed by GPS to a supposed customer location.  In one case I ended up going as directed down a muddy dirt road south of Olancha California looking for the fire station.  When the GPS said, "You have arrived", I found myself looking at open desert with a lone fence post and a big hole in the ground.   I continued on down the road until I reached payment and then asked directions from a local man standing in his yard.  I was on the correct street, but just 1 mile short of my destination.  And I should have come in on a different paved road through the town of Olancha.

And then today, it happened again.  I was being directed by GPS to an address on 67th street West in Mojave California.  I was directed 10 miles south of town and then told to turn west and go 8 miles to 67th Street West.  I did as directed.  I was then told to turn left on 67th street and go 1/4 mile.  I did!  Again, I ended up in open desert in the middle of nowhere.

I ended up calling the customer for directions, only to find out that GPS took me 10 miles to the south of where I needed to be.  If our drones used the same GPS system, that might explain some of the Return to Home problems being posted on this forum.  I don't know that it make a difference, but my phone is an Android phone.  Two bad locations in one week now  makes me very suspicious of the directions when using GPS.

That sounds like bad programming of your phone's navigation app rather than a GPS problem.  GPS is a well tested and very reliable system.

Similar thing happened to me in Florida using a Garmin GPS.  Programed in an address and ended up at an empty field.  Actual location was up the road on the other side of a crossing highway.  Though they may have moved location and check the address on a business card at the location.  Same one I had programmed,
I'd say always take-off and hover, then do what the lady tells you.  "The home point is updated, please check it on the map."

DITTO      

Hummingbird.UAV Posted at 2017-1-27 15:44
Similar thing happened to me in Florida using a Garmin GPS.  Programed in an address and ended up at an empty field.  Actual location was up the road on the other side of a crossing highway.  Though they may have moved location and check the address on a business card at the location.  Same one I had programmed,
I'd say always take-off and hover, then do what the lady tells you.  "The home point is updated, please check it on the map."

You got that right!

There have been numerous reports of Pilot location WAY off.. Mine is reporting 11k feet away. BE CAREFUL ON RTH!

Pretty sure the consensus is that it started with 3.1.2

Could it be this?  https://www.faasafety.gov/files/ ... Flight_Advisory.pdf

My cars GPS hasn't been working right and the other traffic unit that uses GPS is slow to respond for some reason.  Since both are wacked, I'll leave it to the above.  Fwiw, I noticed the FedEx driver had her screen off too but didn't ask her why.  She may just know the route.

Hi I had today Januari 28, 2017 also a problem that the home point set in the DJI app 1,2 km away of the point i fly away (That i know now). Before the drone Phantom Standard  fly away it notified home point recorded. We fly 30 m away and forgot to put the memery card in. I said to my sone bring him home. When the drone was near to use is said use automatic landing.  The app ask at home point or something as the place were you are now. We pointed the last but it start beeping and went to home point. We canceled but the drone didn’t react and fly away. So far away that i couldn't see it. Now my drone is away. We couldn't find it. Tomorrow morning when it is light we go and look again. If i look on the map at de DJI app then it pointed a wrong return to home point.  Also on my sons phone the same problem. If i look at google maps than this program pointed the right place were we take of with the drone. Are there more people with this problem. Hopefully we will find it back.

It is not a problem with the GPS system. The GPS receivers in phones are not good, if you want accurate location, use a good dedicated GPS receiver, something like a Garmin. Phones can be quite a distance out compared to a good GPS receiver.

Also, don't discount the fact that the GPS co-ordinates you have been given can be way out too, it only takes someone copying down the location figures to make a tiny mistake and you will be way out.

And BTW, the GPS receiver in the Phantom aircraft is a quite high spec device, it can be extremely accurate.

I don't know that I agree with the statement that phone GPS units are not accurate.  Our company has been using Samsung Note 3 cellphones for about 3 years now.  In our service program, called Remote Tech, we can select "Map", and the unit will guide us to the next service call turn by turn.  In all that time I have never had it make a location mistake, except when a wrong address was programmed in by our office staff in the first place.  The problem for me, which I mentioned in my first post, began about 2 weeks ago. At least that's when I noticed it.  Two locations in one week were way off as stated in my post.  I'm not saying that there isn't a problem with the Go App program. I'm just saying...there's something fishy going on here!

My Go Home point got screwed up today. All was well at take-off but into the flight I started to loose signal at only about 800' away. Rather than fight it I hit RTH. Video was breaking up bad but I could see that the bird was heading away. I was able to get it cancelled but then GPS dropped out and it went into ATTI. I got it back home but had a heck of a time. It was not responding to sticks and/or responding incorrectly at times. Even though it wasn't windy the drone would fly off in the direction of its choice if I let off the sticks. To land I have to drop down through trees to my driveway so that was a lot of fun. I really feel for the people that have had fly-offs and lost drones. Mine was close today. Hopefully the next time I get to fly everything will be back to normal.

fansa84fe8a4 Posted at 2017-1-28 11:09
Could it be this?  https://www.faasafety.gov/files/notices/2017/Jan/NTTR_17-01_GPS_Flight_Advisory.pdf

My cars GPS hasn't been working right and the other traffic unit that uses GPS is slow to respond for some reason.  Since both are wacked, I'll leave it to the above.  Fwiw, I noticed the FedEx driver had her screen off too but didn't ask her why.  She may just know the route.

Probably not related to the general Go App  3.1.2 issue since the advisory is for the NV area and surrounding states.  The Go App issue is occurring in Florida where I am at.   Besides, I was able to resolve the issue by downgrading the app to 3.1.0 on my tablet.

If you are using Go App version 3.1.2, I suggest disabling Max Distance and set the failsafe to Hover, particularly if you do mistakenly but know ahead of time that you set the home point to what is thought to be your remote location.