Note:
Control point files contain the surveyed coordinates of the control points you added from a total station and then captured with the NavVis device. Refer here for the specific requirements and formats for surveyed coordinates.
After uploading the surveyed control point file, IVION will first perform an alignment check between the recorded control points and the uploaded surveyed control points. The check includes:
A notification if certain lines from the uploaded control point file cannot be recognized. The warning is marked in yellow.
A notification is displayed if any control points from the scan cannot be found in the uploaded control point file. The warning is marked in red.
Example: Control Point “3“ was captured, but not found in the uploaded file.
Warning if certain control points have a large alignment error.
IVION will only show the warning in yellow, if the alignment error is over 10 meters.
Example: Control point that has a large alignment error over 10m.
Left-/ Right-handed Coordinate System Check
In IVION Processing we need the control point coordinates in right-handed coordinate system.
Sometimes, by swapping the left-/right-handed coordinate system (x & y columns), the alignment error will decrease. In this case, a warning will display that the uploaded control point file could be in a left-handed coordinate system. For example:
Double check on your surveyed control point coordinates, if you are sure the coordinates are measured in right-handed coordinate system, click Undo.
If the surveyed control point was indeed in the left-handed coordinate system, and the above warning displayed, click Okay and IVION processing will automatically use the adjusted right-handed control point coordinates.
After the processing, you can download the corrected “Surveyed control points (.csv)“ directly from the processed data:
FAQ
What are control point files?
Control point files contain the surveyed coordinates of the control points added from a total station and captured with the NavVis device.
What happens after I upload a surveyed control point file?
IVION performs an alignment check between the recorded control points and the uploaded surveyed control points.
What does a yellow warning indicate during the alignment check?
A yellow warning indicates that certain lines from the uploaded control point file cannot be recognized.
What does a red warning signify?
A red warning signifies that any control points from the scan cannot be found in the uploaded control point file.
What should I do if I receive a warning about a large alignment error?
If the alignment error is over 10 meters, a yellow warning will be displayed, indicating a large alignment error.
What is the importance of the right-handed coordinate system in IVION Processing?
IVION Processing requires control point coordinates in a right-handed coordinate system to ensure accurate alignment.
What should I do if my coordinates are in a left-handed coordinate system?
If you receive a warning about a left-handed coordinate system, you can confirm if your coordinates are right-handed; if not, click 'Okay' to adjust them.
Can I download the corrected surveyed control points after processing?
Yes, after processing, you can download the corrected 'Surveyed control points (.csv)' directly from the processed data.