Show Posts
1
General / Vertical Misalignment with local control GCP's
« on: February 28, 2017, 02:24:14 AM »
Using the DJI Phantom 3 Professional for stockpile surveys at our mine site. Captured 180 images of an area of about 200m x 100m. Set out 6 GCP's with RTK GPS and imported into Agisoft.
The model aligns with our previous GPS surveys pretty well spot on, in the horizontal plane. However we are getting an error in the vertical alignment. The southern end of the model is ~1.5m low and the North is ~1.5m high, the centre is good. The GCP are spread over the surveyed area and confident in there accuracy. When comparing the model and the GCP's in a separate software the 1.5m discrepancy between the model and the GCP's is present. The errors in the markers are 0.7-1m for all of them. I have manually selected the markers in each photo which didn't help the errors.
I created a model for a second area and ran into the same problem.
How can I rectify this?
Regards
The model aligns with our previous GPS surveys pretty well spot on, in the horizontal plane. However we are getting an error in the vertical alignment. The southern end of the model is ~1.5m low and the North is ~1.5m high, the centre is good. The GCP are spread over the surveyed area and confident in there accuracy. When comparing the model and the GCP's in a separate software the 1.5m discrepancy between the model and the GCP's is present. The errors in the markers are 0.7-1m for all of them. I have manually selected the markers in each photo which didn't help the errors.
I created a model for a second area and ran into the same problem.
How can I rectify this?
Regards
