Incorrect elevation

I have been completed a map now for a construction company in order to document progress on earth moving. I export the map to them and they enter the GCP's. We have noticed that the elevation that shows on the map and the elevation that is shown when downloading the Point Cloud XYZ RGB (TXT) are different. They are off by 600 feet or more. Can you help me understand what we may be doing wrong?

Thank you

Warrior1ops 22. Februar 2022 15:45

Offizieller Kommentar

The GCP realignment process only does the image based results. The OBJ, LAS and TXT are not reprocessed.

In general you are going to get your best results by using 80% overlap (you are using much less than this) and picking 4-6 fixed points around the perimeter of the area. Then tie those points together in GIS software to compare the values. Cloud Compare is also another cool software for doing this which will let you calculate the differences between the two (or more).

Zane 22. Februar 2022 18:47

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I still am confused on how my map after processed shows a correct elevation, however when I download the point cloud, that file shows the elevation to be different by over 600 feet. If my connecting the points by the GIS software, does not affect the point cloud outcome, then what can I do to make sure that is accurate?

Warrior1ops 22. Februar 2022 22:03 0 Stimmen

Keep in mind that the TXT and LAS units are in meters, not feet.

Zane 23. Februar 2022 00:31 0 Stimmen

Is there any way to convert these to feet instead of meters?

Warrior1ops 23. Februar 2022 01:07 0 Stimmen

All of our elevation outputs are in metric for all file types. We just change how it is shown in the browser if the user has indicated imperial units as the preference.

You could open the TXT in Excel and multiple that 3rd column by 3.281.

Zane 23. Februar 2022 01:10 0 Stimmen