CloudCompare forum

I am having an issue loading ground control points in to CloudCompare. I open the csv as an ASCII file and it loads it in the approximately the correct geographic location.

However, if I view the points from above they all have the same x and y coordinates and the 11 points are in a vertical line.
If I view them from the side the Z values seem to be ok.

I have played around with editing the csv and ignore lines and columns but I do not get the x and y coordinates in the right places. It is as though it takes an average of the x and y coordinates. In the app which records the ground control points the positions look good.

Any ideas where I am going wrong here?

Thanks.

Are the GCPs expressed in a projected coordinates system (with linear units) or in a geographic coordinates system (with angular units for X and Y). This may explain that the points all look 'aligned'.

CC doesn't handle geographic coordinate systems. You have to convert them first.

Hi Daniel

Thanks for the reply.

Here is the file with the coordinates.

Yes, looking at the variations between the X and Y coordinates (~10^-3 or 10^-4), I would guess it's angular coordinates.

Do you know which coordinate system they are expressed in? Can you convert them to a 'projected' coordinate system?

They coordinate system should be UTM WGS84. The las files are exported in this format and the coordinates of the GCP's, recorded with the UAV Ground Control app should correspond. The coordinate system selected during the GCP recording was WGS84.

Do you know the EPSG code? (http://epsg.io/). Anyway, CC doesn't convert angular coordinates automagically. You'll have to convert them to linear coordinates first...