I am trying to figure out if there is an error in my workflow or if there is a step I am missing in the software. The error that I am seeing is the final elevation about 200' off.
Workflow
Load photos from test capture area (central Indiana) into ContextCapture Update 11 - 4.4.11.60
Change GPS altitude to WGS 84 ellipsoid because Sea level is not what I want to use as a reference. Now the pose metadata is closer to the elevation of the test area. As you can see in the screen shots below the photogroup pose metadata has adjusted to WGS 84, orthometric height (MSL), geoid EGM96 and the 3D view shows the same. All good.
Screenshots of the initial loading of images
I do not have an GCPs at this location because it is just a test. I set the Block type to Vertical under Additional data because the capture was done all top down. I then move on to aerotriangulation.
The Positioning\georeferencing setting I leave at Use photo positioning metadata for rigid registration because I want to use the pose metadata I just adjusted or advised with inaccurate metadata (I could be wrong here). I also change the Preset under Settings to Keep camera calibration because I have calibrated the camera of my DJI M210 using CC.
Screeshots of the aerotriangulation settings
I let the aerotriangulation complete but do not get the results I expected. The processed images look great in 3D view but the pose metadata is not what I set in the beginning. It keeps changing to WGS 84 (EPSG:4326).
Screenshots of the pose metadata after aerotriangulation
Sure I can change the pose metadata after aerotriangulation but that does not pass thru to the 3MX which results in being 200' off. I realize it is not exact without GCPs but just trying to make sense of why the GPS altitude setting I set did not apply.
Thanks
Sean Keene
Hi Sean,
Editing the value of these boxes in the UI has no effect at all on the imported data, this is only for display purpose (when importing images, the pose and pose metadata).
You have to take care that these values in the EXIF data are properly interpreted while importing the photos, you got this message saying the height is relative to the Sea level, the "Modify" option is the right way to do so.
Regards,
Bruneau
Ok, but why is it not holding the values after the aerotriangulation is complete?
If the purpose of the "Modify" option is to tell CC that the pose data is not Sea level but rather WGS 84 ellipsoid, why does the pose data revert back to original when the aerotriangualtion is complete?
Can anyone else help on this? Running this process thru Pix4D adjust the captures with no issue. Is this a possible bug with ContextCapture?
Create a service request for this issue (https://connect.bentley.com/) and one of us will look at it.