My Mavic has suddenly gotten “weak GPS signal” while flying this week. Is this normal? Flight log pics included.

[Mossiback]

There's no evidence to suggest he has a problem with his compass.
Your suggestion (guess) is unlikely to be any help....

You are correct in that I have no evidence, other than the OP stating that he had compass errors (post 33). The OP also states problems with slowly rotating at hover. A similar problem was fixed by demagnification here:
Compass error. Unstable flight.
The OP stated it went into ATTI mode (although he called it ALTI mode, first post) and a similar problem fixed with Cfixer was posted here:
Compass error after repair
and here:
Compass error during the first flight of the drone
and here:
Mavic Pro Compass Error (Magnetic Interference when camera facing down)

Like I stated before, I have no personal experience with this and these are only guesses as to a solution to his problem. However, they are based on the posted experiences of others.

 

[Spy808]

You are correct in that I have no evidence, other than the OP stating that he had compass errors (post 33). The OP also states problems with slowly rotating at hover. A similar problem was fixed by demagnification here:
Compass error. Unstable flight.
The OP stated it went into ATTI mode (although he called it ALTI mode, first post) and a similar problem fixed with Cfixer was posted here:
Compass error after repair
and here:
Compass error during the first flight of the drone
and here:
Mavic Pro Compass Error (Magnetic Interference when camera facing down)

Like I stated before, I have no personal experience with this and these are only guesses as to a solution to his problem. However, they are based on the posted experiences of others.

I had issues with compass after playing with the simulator on the app for 10-15min and the drone couldn't fly after that (smelt electronic burnt smell)... Compass\Gps errors occurred... Replaced GpS\CompasS n now flys flawless...

 

[Meta4]

You are correct in that I have no evidence, other than the OP stating that he had compass errors (post 33). The OP also states problems with slowly rotating at hover.

A compass error is almost never a fault in the compass.
It is usually a perfectly working compass warning of an additional magnetic field that it has detected.
There still is nothing to suggest he has any problem with his compass.

Like you say, you have no personal experience with this and these are only guesses.
It would be much more productive to work out what his problem actually is rather than suggesting things that are most likely irrelevant.

 

[Ejp1288]

A compass error is almost never a fault in the compass.
It is usually a perfectly working compass warning of an additional magnetic field that it has detected.
There still is nothing to suggest he has any problem with his compass.

Like you say, you have no personal experience with this and these are only guesses.
It would be much more productive to work out what his problem actually is rather than suggesting things that are most likely irrelevant.

Well again, the slow turn (appears to be either going left AND going right depending on the flight) isn't explained. Launched on grassy areas AND sidewalk. Here is a video of it. You can see it slightly turning while hovering:

 

[Meta4]

Well again, the slow turn (appears to be either going left AND going right depending on the flight) isn't explained. Launched on grassy areas AND sidewalk. Here is a video of it. You can see it slightly turning while hovering

that video doesn't show any turning.
The background is rock solid stationary like a still photo but you see one car drive past.

 

[Oregon guns]

You can use the compass in your smartphone at this ultrasensitive.

 

[Ejp1288]

that video doesn't show any turning.
The background is rock solid stationary like a still photo but you see one car drive past.

No, you can look at the left of the screen at the power lines for instance and see how they are moving to the right and more things are being added to the frame like the drone is slightly turning left.

 

[JDawg]

that video doesn't show any turning.
The background is rock solid stationary like a still photo but you see one car drive past.

Maybe you are viewing on a phone? It steadily panned left.

 

[JimCanada]

Not with my experience.
If it's structural as for a building, then yes, it's likely. But not usually for sidewalks or driveways.
Heck, even homes built on slabs don't have rebar. No interference warnings on the floor of my home or my dad's for my M2 or my P3. I have gotten them in buildings I work in though.

Well up here in Canada we do keeps it from cracking , im only 58 what would i know ?

 

[Meta4]

No, you can look at the left of the screen at the power lines for instance and see how they are moving to the right and more things are being added to the frame like the drone is slightly turning left.

I was watching the centre, rather than the side.
The tiny amount of movement I see doesn't look like it's enough to be alarmed about.

 

[Ejp1288]

I was watching the centre, rather than the side.
The tiny amount of movement I see doesn't look like it's enough to be alarmed about.

Well here is another example I took after taking off from my front lawn on cardboard. This is a lot more extreme. Towards the end I lower it and or raise it and it immediately still starts turning to the right on its own in hover.

 

[IronReel]

Calibrating isn't going to fix anything. That's not what compass calibrating is for.


It's always much more useful to post a link to the Phantomhelp report for your incident.
But your case looks pretty clear even from just what you posted.
It's almost certain that you launched from a magnetically bad location, most commonly reinforced concrete.
That's given you a yaw error and caused the other issues.
NEVER launch from steel or reinforced concrete surfaces.

I'm sure most the people flying their drones will know when they are on reinforced concrete surfaces

 

[Meta4]

I'm sure most the people flying their drones will know when they are on reinforced concrete surfaces

But not everyone here.
See posts #14, # 25 and #34

 

[Meta4]

Well here is another example I took after taking off from my front lawn on cardboard. This is a lot more extreme. Towards the end I lower it and or raise it and it immediately still starts turning to the right on its own in hover.

What is turning?
Is it the mavic rotating or is it the gimbal creeping?

 

[Ejp1288]

What is turning?
Is it the mavic rotating or is it the gimbal creeping?

I can’t tell. I think it’s the mavic rotating. It rotates too slow for me to watch if the drone is turning or not. Neither should be doing it though. I feel like it’s the drone though because it turns quite a bit.

DJI reviewing flight records now.

 

[Ejp1288]

What is turning?
Is it the mavic rotating or is it the gimbal creeping?

Do you thinking launching from an asphalt parking lot or street is fine?

 

[Meta4]

Do you thinking launching from an asphalt parking lot or street is fine?

Unless there is some steel pipework etc underneath, it usually would be.

 

[77ricco]

Very interesting!

I’ll test this tomorrow. If I can’t launch on a sidewalk. Where do you suggest I launch? Grass seems to be too high usually to launch. Where do you like to launch from?

Sometimes I launch it from my hand.

 

[77ricco]

Very interesting!

I’ll test this tomorrow. If I can’t launch on a sidewalk. Where do you suggest I launch? Grass seems to be too high usually to launch. Where do you like to launch from?

Sometimes I launch it from my hand.

 

[ToddCarey]

One correction, concrete surfaces ARE NOT half steel. Lighter weight surfaces have a wire mesh (usually a 4"x4" nesh), while heavy duty surfaces will have steel reinforcing bars (size will vary with the load design, but usually they are 10" to 12" OC), but they are NOT half steel. It appears to me the compasses in our units are very sensitive, and even a placement of several inches one side to another will affect the initialization of the compass. I agree it is the best to avoid it altogether, but it does make sense where someone may have launched from a driveway, and later get an error.