100m Geoid Error - OSGB36 + ODN Height (EPSG::7405)

[RoryG]

Hi, since updating to Metashape 1.8 when I convert from WGS84 to OSGB36 + ODN Height using the installed OSGM15 tif geoid the heights are all exactly 100m too high. When I convert the camera positions in Metashape I get (using one image as an example):

WGS84: 57.67697 -2.735643 179.192; OSGB36: E 356224.48 N 865474.163 H: 228.992

Transforming using the OS Coordinate Converter I get:

WGS84: 57.67697 -2.735643 179.192; OSGB36: E 356224.48 N 865474.163 H: 128.991

Somehow 100m is getting added to the height. I have used the Metashape conversion without issue until I upgraded to 1.8, is this a known issue or bug?

Thanks,

Rory

[Alexey Pasumansky]

Hello Rory,

Can you please check, if you still observe the problem in 1.8.1 pre-release build 13845:

http://download.agisoft.com/metashape-pro_1_8_1_x64.msi                             Windows
http://download.agisoft.com/metashape-pro_1_8_1.dmg                                    Mac OS
http://download.agisoft.com/metashape-pro_1_8_1_amd64.tar.gz                   Linux

[RoryG]

Hi Alexey,

Unfortunately not, the problem still exists. Will the 1.8 projects open in 1.7.6? If this can't be sorted by the time I need to export the outputs I will need to use the older version where the problem didn't exist.

Thanks,

Rory

[Alexey Pasumansky]

Hello Rory,

Yes, you should be able to open the projects saved in version 1.8 using version 1.7.6.

[RoryG]

Hi Alexey, I can confirm my projects are opening fine in 1.7.6 and no longer have the geoid / conversion issue.

[Alexey Pasumansky]

Hello Rory,

The fix will be implemented in the next 1.8.1 update, as soon as pre-release is updated, I will let you know.

[mikeyjump]

Alexey - I discovered this same error after a big sparse cloud process on 12,000 images. I have successfully reopened in 1.7.6 and markers are now correctly positioned. However, the altitude data is still offset against the cameras. Am I safe to leave it as it is, or should I apply an offset to the altitudes? I'm not sure it's exactly 100m either, probably a bit less, and I'm not even sure if it's consistent across all the images. Quite a bug!

[RoryG]

Hello Rory,

The fix will be implemented in the next 1.8.1 update, as soon as pre-release is updated, I will let you know.

Thanks Alexey, good to know. 1.7.6 has been working fine for this project.

[Alexey Pasumansky]

Hello Rory,

Please check Metashape 1.8.1 build 13875 pre-release (same links, but updated packages):
http://download.agisoft.com/metashape-pro_1_8_1_x64.msi                             Windows
http://download.agisoft.com/metashape-pro_1_8_1.dmg                                    Mac OS
http://download.agisoft.com/metashape-pro_1_8_1_amd64.tar.gz                   Linux

[RoryG]

Hi Alexey,

Can you confirm that the mainstream 1.8.1 release has the offset issue fixed? I'm still on 1.7.6 but would like to upgrade due to additional features.

Thanks,

Rory

[Alexey Pasumansky]

Hello Rory,

Version 1.8.1 has been released and based on our testing we assume that the issue is fixed now. If you still observe any issues after installing 1.8.1, please let me know.

[RoryG]

Perfect, thank you