Mini 3 pro GPS issue

[peterpdevil]

Hi,

I've been experiencing several GPS issues. The last one happened as I was shooting an hyperlapse at a ground speed of 0.1m/s (in other words almost static) at 40m altitude, in a urban area but without tall buildings in the immediate vicinity. I was catching 32 satellites all along the flight, until I lost them all, within a couple of seconds (4s to be precise). I never lost the connection to the RC, and video feedback was no problem. DJI is now analysis the flight data.

This happened to me before in a different situation and ended up in a crash. The drone was replaced by DJI without explanation of what could have happened. So this instance I describe above happened on my second brand new mini 3 pro.

I suspect issues with the GPS of the series.

Any similar experience?

Pierre

 

[LoudThunder]

The drone was replaced by DJI without explanation of what could have happened.

Just curious, was the Drone replaced under warranty or under the DJI Car Refresh? I had a Mini 2 replaced under the Care Refresh and the replacement was defective and DJI replaced that Drone under the warranty and they even sent me Coupons for a Free set of propellers and a new battery from the DJI Store as a way to make up for the mess up…

 

[RUFFSTUFF]

Just curious, was the Drone replaced under warranty or under the DJI Car Refresh?

I sure hope not...! The drone just came out and there's plenty of people waiting for their orders to be filled!

 

[peterpdevil]

Just curious, was the Drone replaced under warranty or under the DJI Car Refresh? I had a Mini 2 replaced under the Care Refresh and the replacement was defective and DJI replaced that Drone under the warranty and they even sent me Coupons for a Free set of propellers and a new battery from the DJI Store as a way to make up for the mess up…

I didn't subscribe to DJI care. The drone was replaced under the guarantee.

 

[peterpdevil]

I sure hope not...! The drone just came out and there's plenty of people waiting for their orders to be filled!

Sorry to say it was I got my first one in about a week (a bit longer than usual but faster than announced by DJI store), even though we were still under lockdown. I brought it broken a monday to a DJI store (the day of Shanghai delockdown) and got the replacement the following saturday.

 

[Meta4]

I was catching 32 satellites all along the flight, until I lost them all, within a couple of seconds (4s to be precise).

There are two possibilities.
One is a glitch in the drone, like a loose connection.
The other is GPS jamming, but that is quite rare.
If you post your flight data, that might help understand the issue better.

This happened to me before in a different situation and ended up in a crash.

This is puzzling.
First, losing GPS shouldn't crash the drone.
It should leave the drone without horizontal position holding, drifting on the wind, but fully controllable.

Second, having two different drones with a loose connection affecting GPS seems unlikely.

 

[Meta4]

DJI is now analysis the flight data.

Post your flight data here and you'll get an explanation of what the analysis shows quicker than DJI.

 

[peterpdevil]

First, losing GPS shouldn't crash the drone.
It should leave the drone without horizontal position holding, drifting on the wind, but fully controllable.

Sorry, I didn't make myself clear. The crash is the consequence of the drone losing GPS, drifting quite fast on the wind, me not understanding what was happening, etc. (airdata here)

 

[peterpdevil]

Post your flight data here and you'll get an explanation of what the analysis shows quicker than DJI.

Here it is (link to airdata). Thanks for your help

Before B (referring to GPS data), shooting an hyperlapse, 32 satellites, drops to 0 in 2 seconds (while drone is basically hovering). Then I pushed it up (learnt from experience) and brought it back home manually with video (never lost RC connection nor video during the incident).

 

[Meta4]

Here it is (link to airdata). Thanks for your help

Before B (referring to GPS data), shooting an hyperlapse, 32 satellites, drops to 0 in 2 seconds (while drone is basically hovering). Then I pushed it up (learnt from experience) and brought it back home manually with video (never lost RC connection nor video during the incident).

Your GPS sat numbers dropped and fluctuated after 17:36.2.
The sat numbers dropped as low as 0, but was >0 almost all of the time and fluctuated up and down.
Even when the numbers rose beyond 20 sats, the GPS reliability stayed low until 18:57.2.

This is quite abnormal.
How far away was the previous incident?
Have you flown since at this location?
If you fly somewhere >10 km away, does teh drone behave normally?

 

[peterpdevil]

Your GPS sat numbers dropped and fluctuated after 17:36.2.
The sat numbers dropped as low as 0, but was >0 almost all of the time and fluctuated up and down.
Even when the numbers rose beyond 20 sats, the GPS reliability stayed low until 18:57.2.

This is quite abnormal.
How far away was the previous incident?
Have you flown since at this location?
If you fly somewhere >10 km away, does teh drone behave normally?

The first incident wasn't far (data here). As said, it was with a first drone that was then replaced. But I've been mostly flying around here without issue. I've just been back to the exact same location of the second incident during the lunch break and did not meet any problem.

 

[Phantomrain.org]

Just taking a look at the map , are you maybe flying behind a building as there seem to be quite in few in that pathway ? That would explain the zero sats in a instant.

Phantomrain.org
Gear to fly in the Rain. Land on the Water.

 

[Meta4]

Just taking a look at the map , are you maybe flying behind a building as there seem to be quite in few in that pathway ? That would explain the zero sats in a instant.

The number of sats didn't drop to zero in an instant.
The data shows a more complex situation.

 

[Meta4]

I don't like to jump to a conclusion about GPS jamming because that's quite rare.

A GPS jammer isn't necessarily permanently operating.
But if you had similar things happening in the same area on different occasions, that is suspicious.

 

[Phantomrain.org]

Just looking as a Pilot , this is kind of a Sketchy take off point , and not sure I would have taken it up at that angle.
Im sure you will figure it out , but its not an angle I would have taken as it to close that building. I notice when others fly in the city they have an open road that they follow which allows the signal to clear.

Interesting , but not a flight angle I would have taken .




Phantomrain.org
Gear to fly in the Rain. Land on the Water.

 

[Meta4]

This shows how the number of sats fluctuated for a minute and a half.
The numbers were all over the place but was >0 for almost all of the time.
Climbing from 130 ft to 250 ft made no difference.
Even with sat numbers well above 20, the GPS reliability stayed low (less than 4/5).
The white areas under the thick green line show good GPS at the start and end of the incident.

 

[peterpdevil]

Just looking as a Pilot , this is kind of a Sketchy take off point , and not sure I would have taken it up at that angle.
Im sure you will figure it out , but its not an angle I would have taken as it to close that building. I notice when others fly in the city they have an open road that they follow which allows the signal to clear.

Interesting , but not a flight angle I would have taken .

View attachment 150152


Phantomrain.org
Gear to fly in the Rain. Land on the Water.

Thanks for your advice. GPS signals were perfect at the time of take off, and all the way to the easterner point of the trajectory. This makes me think that the root cause is elsewhere.

 

[peterpdevil]

Your GPS sat numbers dropped and fluctuated after 17:36.2.
The sat numbers dropped as low as 0, but was >0 almost all of the time and fluctuated up and down.
Even when the numbers rose beyond 20 sats, the GPS reliability stayed low until 18:57.2.

This is quite abnormal.
How far away was the previous incident?
Have you flown since at this location?
If you fly somewhere >10 km away, does teh drone behave normally?

NB: I replied your message but it has to be moderated for some reason.

 

[Derlisz]

Hi,

I've been experiencing several GPS issues. The last one happened as I was shooting an hyperlapse at a ground speed of 0.1m/s (in other words almost static) at 40m altitude, in a urban area but without tall buildings in the immediate vicinity. I was catching 32 satellites all along the flight, until I lost them all, within a couple of seconds (4s to be precise). I never lost the connection to the RC, and video feedback was no problem. DJI is now analysis the flight data.

This happened to me before in a different situation and ended up in a crash. The drone was replaced by DJI without explanation of what could have happened. So this instance I describe above happened on my second brand new mini 3 pro.

I suspect issues with the GPS of the series.

Any similar experience?

Pierre

I have witnessed identical behaviour in Mavic 2 a few days back. It resulted in loss of control, crash and total loss.

 

[Meta4]

I have witnessed identical behaviour in Mavic 2 a few days back. It resulted in loss of control, crash and total loss.

Are you sure that's what happened?
Losing GPS does not cause loss of control.