Incorrect EXIF GPS and Elevation

[Paulo Lobo]

"This is so so so bad for dji image..."

To maybe 10 people worldwide.

Your very wrong !!
Go to google and google it !

Many people asking dji to repair this my friend !

 

[sar104]

DJI Phantom 4, dji phantom 4 pro, dji mavic pro, inspire 1, inspire 2, all of them have the value gps altitude in EXIF.

Also the softwares to work the fotos ask for the gps altitude in the EXIF fotos, so its necessary.

If you dont understand that, its no problem.

Dji as assume that there is a problem in the firmware, the first dji mavic 2 pro firmware was with this information in the EXIF fotos, the second firmware, and the last ones, there is no GPS Altitude in EXIF.

So we must wait for the repair.

Bye.

No - as I showed above, it's not the GPS altitude in those EXIFs - it's the absolute barometric altitude, which accounts for the significant errors that others, such as @Meta4, have pointed out over the years. That is not new to the M2. You can easily extract the actual GPS altitude from the log files for comparison. The original M2 firmware had a different bug that put a meaningless absolute altitude into the EXIF data, but that was fixed with the first firmware update.

 

[Paulo Lobo]

No - as I showed above, it's not the GPS altitude in those EXIFs - it's the absolute barometric altitude, which accounts for the significant errors that others, such as @Meta4, have pointed out over the years. That is not new to the M2. You can easily extract the actual GPS altitude from the log files for comparison. The original M2 firmware had a different bug that put a meaningless absolute altitude into the EXIF data, but that was fixed with the first firmware update.

I understand what your saying, but its not easy to get the logs and join them to the fotos and be able to make the Bentley Concept work with them or other software.

Perhaps to have a software that makes this auto mode, get the info of the foto, go to the log file and remove the altitude and insert it in the foto EXIF ??

 

[sar104]

I understand what your saying, but its not easy to get the logs and join them to the fotos and be able to make the Bentley Concept work with them or other software.

Perhaps to have a software that makes this auto mode, get the info of the foto, go to the log file and remove the altitude and insert it in the foto EXIF ??

I completely agree - it's not ideal at all. And it would be trivial to insert the GPS altitude either instead of, or in addition to, the absolute barometric altitude. And they shouldn't label it GPS altitude when it is barometric altitude. I just doubt that it is very high on their priority list. Perhaps if enough people point out the actual issue with technical support, rather than just complaining that the GPS altitude is missing or wrong, it might get fixed. Maybe a few carefully worded support tickets will get their attention.

 

[Paulo Lobo]

I understand what your saying, but its not easy to get the logs and join them to the fotos and be able to make the Bentley Concept work with them or other software.

Perhaps to have a software that makes this auto mode, get the info of the foto, go to the log file and remove the altitude and insert it in the foto EXIF ??

Look, im working with DroneDeploy and with Bentley.



Bentley was able to make altitude data by "looking" at the fotos and check if there was altitude by comparing images.... But Bentley warn that there was Altitude zero on the fotos taken by mavic 2 pro today.

 

[Paulo Lobo]

I completely agree - it's not ideal at all. And it would be trivial to insert the GPS altitude either instead of, or in addition to, the absolute barometric altitude. And they shouldn't label it GPS altitude when it is barometric altitude. I just doubt that it is very high on their priority list. Perhaps if enough people point out the actual issue with technical support, rather than just complaining that the GPS altitude is missing or wrong, it might get fixed. Maybe a few carefully worded support tickets will get their attention.

We just need a altitude vale for the foto, that will be acepted by dronedeploy or Bentley or Autodesk remake, or other... A real value, and a value that can be acepted by this app !

Thanks SAR104 !

 

[Paulo Lobo]

Hi !

Today i made with dji mavic 2 pro some tower mapping with dronedeploy, and i was checking the fotos now !
The fotos made by the dronedeploy capturing have the altitude gps EXIF on fotos fully ok !!

So this is a problem with dji 4 go aplication ??


Check the dronedeploy fotos here :


DJI_0218.JPG and 2 more files

 

[sar104]

Hi !

Today i made with dji mavic 2 pro some tower mapping with dronedeploy, and i was checking the fotos now !
The fotos made by the dronedeploy capturing have the altitude gps EXIF on fotos fully ok !!

So this is a problem with dji 4 go aplication ??


Check the dronedeploy fotos here :


DJI_0218.JPG and 2 more files

No - the EXIF data in the image files on the aircraft is not determined by the app, and the EXIF data in the files you posted above are identical to those from M2 images captured when running under DJI GO 4. As I explained earlier, they already have absolute altitude data, in two separate fields:

GPS Altitude: 50.5 m Above Sea Level​

Absolute Altitude: +50.53​

The problem is that despite the label, that is not GPS altitude - it is absolute barometric altitude which is, in general, wildly inaccurate. I don't know how to explain this any more clearly.

 

[Paulo Lobo]

Hi,

Problem is solved by dji !

Last dji 4 go and last firmware !

 

[Keule]

Problem is solved by dji !

If that's working for you - fine.

But still, as @sar104 tries to explain in previous posts, that altitude given in the image above, that altitude is not a GPS altitude.

Look at Google Earth Pro and locate your position 40° 41' 42.631777" -8° 31' 58.458420" - GE reports that this position is at 76m AMSL. Flying with your aircraft ~50m above that point should give you a reading of ~127m.

At the end your EXIF reader should display 127 m GPS altitude.
(But it doesn't. It displays the barometric height 47.3m)

So, DJI has still to fix that issue.

 

[Paulo Lobo]

I dont understand, today i went outside again and take some fotos, gps altitude is again on ZERO !
I really dont understand this !!

The mavic 2 pro is with last dji go 4 and last firmware...

Look :

 

[sar104]

I dont understand, today i went outside again and take some fotos, gps altitude is again on ZERO !
I really dont understand this !!

The mavic 2 pro is with last dji go 4 and last firmware...

Look :



View attachment 60704


View attachment 60705

Once again - it's not actually GPS altitude being reported, it's barometric. And while I'd have to see one of your actual image files to be certain, I suspect that your EXIF reader is simply changing any negative absolute altitude to zero. So if the barometric altitude is above zero it reports it, while if it is below zero it just reports zero.

 

[Paulo Lobo]

Once again - it's not actually GPS altitude being reported, it's barometric. And while I'd have to see one of your actual image files to be certain, I suspect that your EXIF reader is simply changing any negative absolute altitude to zero. So if the barometric altitude is above zero it reports it, while if it is below zero it just reports zero.

Before i use EXIF PILOT app i just check with the windows foto details and also there was no value there, only a zero.
This is so weird ! I was at 30 meters altitude from the sea in the real deal when i take that foto !

 

[Paulo Lobo]

Before i use EXIF PILOT app i just check with the windows foto details and also there was no value there, only a zero.
This is so weird ! I was at 30 meters altitude from the sea in the real deal when i take that foto !

Do you know if its possible to work in simulator to test the altitude with simulator ?

 

[sar104]

Before i use EXIF PILOT app i just check with the windows foto details and also there was no value there, only a zero.
This is so weird ! I was at 30 meters altitude from the sea in the real deal when i take that foto !

Without seeing an actual image file reporting zero altitude so that I can extract the full EXIF data there is no more that I can do to help you.

 

[Paulo Lobo]

Without seeing an actual image file reporting zero altitude so that I can extract the full EXIF data there is no more that I can do to help you.

Here you have it

DJI_0005.JPG

 

[sar104]

Here you have it

DJI_0005.JPG

The EXIF data on altitude in that image look as follows:

GPS Altitude Ref : Below Sea Level​

Absolute Altitude : -76.69​

Relative Altitude : +31.60​

GPS Altitude : 0 m Above Sea Level​

The absolute barometric altitude is reporting below sea level, as I expected, but the GPS altitude field, which simply mirrors the absolute barometric altitude when that is positive, has simply been set to zero for negative altitudes. Your EXIF readers are just reading the GPS altitude field - hence they read real (but barometric) altitudes when positive and zero when negative.

 

[Paulo Lobo]

The EXIF data on altitude in that image look as follows:

GPS Altitude Ref : Below Sea Level​

Absolute Altitude : -76.69​

Relative Altitude : +31.60​

GPS Altitude : 0 m Above Sea Level​

The absolute barometric altitude is reporting below sea level, as I expected, but the GPS altitude field, which simply mirrors the absolute barometric altitude when that is positive, has simply been set to zero for negative altitudes. Your EXIF readers are just reading the GPS altitude field - hence they read real (but barometric) altitudes when positive and zero when negative.

So the relative altitude is 31.60meters, this is the real one that can be use ?

 

[Paulo Lobo]

What aplication are you using to read this :

GPS Altitude Ref : Below Sea Level
Absolute Altitude : -76.69
Relative Altitude : +31.60
GPS Altitude : 0 m Above Sea Level

The EXIF pilot does not show that on XMP :

 

[Keule]

What aplication are you using to read this :

exiftool