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Home Point Update in Wrong Place, Solved (at least for my Mavic 3). It had to do with the FLY SAFE DATABASE.

Don Testme

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My Home Point Update, suddenly started putting my Mavic 3 drone's take off location several blocks away from my actual launch location. I recalibrated the compass and IMU but this didn't work. But then I realised I hadn't updated the FLY SAFE DATA BASE that the program was requesting be done on the startup screen. Once I updated the FLY SAFE DATABASE, the drone's homepoint / launch position became accurate again.
 
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My Home Point Update, suddenly started putting my Mavic 3 drone's take off location several blocks away from my actual launch location. I recalibrated the compass and IMU but this didn't work. But then I realised I hadn't updated the FLY SAFE DATA BASE that the program was requesting be done on the startup screen. Once I updated the FLY SAFE DATABASE, the drone's homepoint / launch position became accurate again.
The Flysafe Database update has nothing at all to do with the homepoint recoring.
Neither does the compass or IMU, so it's no mystery that recalibrating didn't help.

Recording the homepoint is completely dependent on the GPS receiver in your drone and nothing else.
The most likely explanation for having a homepoint several blocks away is that you launched without a homepoint and the drone recorded a homepoint when it got good GPS location data sometime after you launched.
Your recorded flight data would confirm if this was the case and if it wasn't, it should show why.
 
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The Flysafe Database update has nothing at all to do with the homepoint recoring.
Neither does the compass or IMU, so it's no mystery that recalibrating didn't help.

Recording the homepoint is completely dependent on the GPS receiver in your drone and nothing else.
The most likely explanation for having a homepoint several blocks away is that you launched without a homepoint and the drone recorded a homepoint when it got good GPS location data sometime after you launched.
Your recorded flight data would confirm if this was the case and if it wasn't, it should show why.
The drone continued recording a homepoint, at rest, just before lift off and just after lift off. This home point kept being off by 4 blocks. After this consistent home point displacement, perhaps my endeavors, as stated in my original post, were pure coincidence in correcting the problem. Why the drone decided to correct it's location after the Flysafe Data Base update, I guess is coincidence. I'm not going to post my flight data. Sorry, but I'm a little to lazy. Perhaps, what I did worked, perhaps, it was just a coincidence. If anyone has this problem, they can try what I did or upload their flight data for your purview, if they can't get it to correct position.
 
The drone continued recording a homepoint, at rest, just before lift off and just after lift off. This home point kept being off by 4 blocks.
In that case, what the flight data would show was that the drone recorded a homepoint while the GPS data quality was marginal and inaccurate, and that it updated when the data was more reliable.
It's disappointing that you aren't interested in contributing to the forum's collective understanding.
Perhaps, what I did worked
There's no perhaps to it.
It had nothing to do with what you did.

Was it a one-off incident?
If it was related to the update, it should have happened consistently every time.
And other users would have reported similar events.
But because the Flysafe Database updating is 100% unrelated to anything to do with recording a home point, it couldn't have had any effect.
perhaps, it was just a coincidence.
Not perhaps .. it was 100% coincidence.
If anyone has this problem, they can try what I did or upload their flight data for your purview, if they can't get it to correct position.
Don't wast any effort on this nonsense.
 
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In that case, what the flight data would show was that the drone recorded a homepoint while the GPS data quality was marginal and inaccurate, and that it updated when the data was more reliable.
It's disappointing that you aren't interested in contributing to the forum's collective understanding.

There's no perhaps to it.
It had nothing to do with what you did.

Was it a one-off incident?
If it was related to the update, it should have happened consistently every time.
And other users would have reported similar events.
But because the Flysafe Database updating is 100% unrelated to anything to do with recording a home point, it couldn't have had any effect.

Not perhaps .. it was 100% coincidence.

Don't wast any effort on this nonsense.
Ok. I give. I know you're probably tired of telling people how to extract flight info, but could you tell me how. And once I obtain it, where do you want me to put it. Do I just attach the file to my messages?
 
Ok. I give. I know you're probably tired of telling people how to extract flight info, but could you tell me how. And once I obtain it, where do you want me to put it. Do I just attach the file to my messages?
No problem ...

Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report on the flight data.
Come back and post a link to the report it provides, or just post the .txt file.
 
No problem ...

Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report on the flight data.
Come back and post a link to the report it provides, or just post the .txt file.
Here are 3 of my flights. (A) is where the home point was recorded. In the middle of a field? Then the second, in a totally different neighborhood. I used AirData to find the right ones. And finally (the third log) after doing compass, imu calibration and flysafe data base update, an accurate HP.

I don't know what the drone was doing or why it kept putting my home point in that field, but it corrected after the things I did. It only seemed to fix itself after the fly safe database was updated. See .TXT files below. the first 2 are erroneous home points, the third is a true home point.
 

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  • DJIFlightRecord_2022-06-11_[17-45-36].txt
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  • DJIFlightRecord_2022-06-11_[17-52-49].txt
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  • DJIFlightRecord_2022-06-11_[18-37-50].txt
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Last edited:
No problem ...

Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report on the flight data.
Come back and post a link to the report it provides, or just post the .txt file.
It Looks my my GPS was all out of whack. Why it wasn't picking up satellites , I don't know. After the calibrations and fly safe database fixes, did the GPS start working normally again.
 
It Looks my my GPS was all out of whack. Why it wasn't picking up satellites , I don't know. After the calibrations and fly safe database fixes, did the GPS start working normally again.
There's definitely something going on there.

Here's what I see in the first flight.
I've seen a couple of flight logs like this where the drone does not have good GPS location data or a recorded home point, but the app shows GPS mode.
In the first flight, the GPS reliability was 2/5 (not reliable) until 34.1 seconds, with the homepoint being recorded half a second later when GPS reliability was 4/5.

You had flown a short distance in that time, but without GPS we have no speed or distance data to know how far.
GPS dropped back to 2/5 again at 58.7 sec.
AT the time the drone was 16 ft high and the terrain appears to be clear of obstructions that could have blocked GPS, so the cause of this is of concern.
It was a short flight, only lasting 1:17.9, but GPS was fluctuation between 2/5-4/5 the whole time.

Was there anything fitted to the top-front of the drone that could partially block GPS reception?
If not this looks like a problem with the GPS receiver.
 
There's definitely something going on there.

Here's what I see in the first flight.
I've seen a couple of flight logs like this where the drone does not have good GPS location data or a recorded home point, but the app shows GPS mode.
In the first flight, the GPS reliability was 2/5 (not reliable) until 34.1 seconds, with the homepoint being recorded half a second later when GPS reliability was 4/5.

You had flown a short distance in that time, but without GPS we have no speed or distance data to know how far.
GPS dropped back to 2/5 again at 58.7 sec.
AT the time the drone was 16 ft high and the terrain appears to be clear of obstructions that could have blocked GPS, so the cause of this is of concern.
It was a short flight, only lasting 1:17.9, but GPS was fluctuation between 2/5-4/5 the whole time.

Was there anything fitted to the top-front of the drone that could partially block GPS reception?
If not this looks like a problem with the GPS receiver.
I had nothing attached to the drone. I had just taken the drone out of my car trunk. It was in my trunk from 11am to about 5pm in the heat. A black car as well. Maybe the heat affected the GPS temporarily. The last flight, the GPS worked normally. Maybe as I toyed with it in my house @73 degrees F, the internal circuitry was able to cool down.
 
I had nothing attached to the drone. I had just taken the drone out of my car trunk. It was in my trunk from 11am to about 5pm in the heat. A black car as well. Maybe the heat affected the GPS temporarily. The last flight, the GPS worked normally. Maybe as I toyed with it in my house @73 degrees F, the internal circuitry was able to cool down.
Heat might be a factor.
The GPS unit is rated to a max temperature and if that was exceeded, perhaps that could cause it to act erratically.
Keep an eye on that.

Here's what I see in the 2nd flight
GPS was good (4/5) at the start and a home point was recorded just a few seconds after startup.
But 12 seconds later at 2:29.1, GPS reliability dropped to 2/5 and stayed there while you climbed to nearly 400 ft.
It only stayed good for a second and dropped again until 4:28.7 and recorded a second homepoint shortly afterward.
It spent the rest of the flight blinking in and out (mostly out) of good GPS.

There's definitely something wrong.
It shows 2/5 even though there were 17 sats locked.
 
I had nothing attached to the drone. I had just taken the drone out of my car trunk. It was in my trunk from 11am to about 5pm in the heat. A black car as well. Maybe the heat affected the GPS temporarily. The last flight, the GPS worked normally. Maybe as I toyed with it in my house @73 degrees F, the internal circuitry was able to cool down.
Thanks for providing the data.
It was an interesting situation and not one that's I've seen before.
If it was just the temp and it works properly from now on, that's great.
 
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