Mavic air geotag workaround

[hansg]

Dear Mavic air owners,

There has been a lot of complaints about the low precison exif geotags in the images produced by Mavic air, and without a fix, mapping and image matching will be impossible or at least very difficult. Here is my workaround that I've been using this summer.

The workaround is based on exiftool by Philip Harvey. Exiftool is a cli-based exif reader and writer. Personally I installed exiftool with brew on my Mac, but it works on Linux and Windows as well. Search the web for other installation options.

"Exiftool -a" lists all exiftags and luckily there exits two different Latitude/Longitude tags. The crippled EXIF:GPSlatitude and EXIF:Longitude that seems to be the default choice in most mapping programs, but also the seemingly uncrippled XMP:Latitude and XMP:Longitude tags. The following command replaces the crippled coordinates with the higher precision versions.

exiftool '-EXIF:GPSLatitude<XMP:Latitude' '-EXIF:GPSLongitude<XMP:Longitude' filename.jpg

The command can use wildcards so it's quick to fix all files in a directory.

/hans

 

[autoperformance]

Could you do a video on youtube ?

 

[AggieBQ86]

So if we use *.jpg instead if filename.jpg it would modify all the pictures in the folder?

 

[AggieBQ86]

What am I doing wrong? View media item 2195

 

[hansg]

What am I doing wrong? View media item 2195

Case sensitive - my drone uses .JPG!

 

[sparky1958]

I had the same error. Replaced the single quotation marks with double quotation marks in the command and it then ran fine:

exiftool "-EXIF:GPSLatitude<XMP:Latitude" "-EXIF:GPSLongitude<XMP:Longitude" filename.jpg

 

[AggieBQ86]

Dear Mavic air owners,

There has been a lot of complaints about the low precison exif geotags in the images produced by Mavic air, and without a fix, mapping and image matching will be impossible or at least very difficult. Here is my workaround that I've been using this summer.

The workaround is based on exiftool by Philip Harvey. Exiftool is a cli-based exif reader and writer. Personally I installed exiftool with brew on my Mac, but it works on Linux and Windows as well. Search the web for other installation options.

"Exiftool -a" lists all exiftags and luckily there exits two different Latitude/Longitude tags. The crippled EXIF:GPSlatitude and EXIF:Longitude that seems to be the default choice in most mapping programs, but also the seemingly uncrippled XMP:Latitude and XMP:Longitude tags. The following command replaces the crippled coordinates with the higher precision versions.

exiftool '-EXIF:GPSLatitude<XMP:Latitude' '-EXIF:GPSLongitude<XMP:Longitude' filename.jpg

The command can use wildcards so it's quick to fix all files in a directory.

/hans

I also changed the single quotation marks ( ' ) to double quotation marks ( " ). The program ran with these warnings but it changed the coordinates.

Warning: Bad MakerNoteDJI directory - DJI_0949.JPG
Warning: [minor] Maker notes could not be parsed - DJI_0949.JPG

I'll let you know what happens once I process the photos with Dronemapper.

 

[hansg]

Nice that it seems to work. I have also seen the warnings. No clue what they actually means though.

I have processed my mission images with Agisoft PhotoscanPro. Without replacing the low precison coordinate tags I usually got an absolute error of around 20 meters. The scaling of the models were also off. After the workaround and replacing the tags the error are commonly less than 3 meters.

 

[andre.schoeman]

Hi all,

I logged a support call today and got this reply:

Dear Andre,

Thank you for contacting DJI Support.

In regards to the issue you have encountered, wherein "the Photos taken by drone not accurate, is out by 15-30m and this is caused because the Latitude and Longitude ignore some of the decimal values of the seconds reading in the HH:MM:SS value". This has been forwarded to our Research and Development Department, and as per advised, the GPS latitude and Longitude which show in pictures properties will Improve accuracy in the next firmware. Thank you so much for your understanding.

If you have any questions, please feel free to contact DJI Europe Support, Mon-Fri 8:30 AM - 5:00 PM (UTC+1) via the following three channels:

Tel Support: +31 20 654 5202
Email: [email protected]
Online Support: DJI Support – Here for You – DJI

Have a great day!


DJI Customer Support

Website: DJI Support – Here for You – DJI

YouTube: DJI Support

 

[andre.schoeman]

Hi all,

The Lat Long decimal value was fixed with latest firmware update, see attached image.

Regards,

Andre

 

[autoperformance]

Good

 

[autoperformance]

Oh yess... good news.

 

[hansg]

Finally! I can confirm that the latest firmware upgrade fixed the flawed GPS:Latitude and GPS:Longitude exif entries. The values now corresponds closely to the XMP counterparts (although not exactly identical).

/hans