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Author Topic: Ground Control Points error  (Read 5107 times)

ccrystal98

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Ground Control Points error
« on: January 09, 2017, 11:32:09 AM »
Hi,

I used 8 Ground Control Points in georeferencing and chose 'manully place markers'. I found that in the generated processing report there is a table listing the X error (m), Y error (m), Z error (m), Error (m), Projections,  Error (pix) for each GCP and also a total of them.

I am wondering how to interpret them. Also, within which range, for example for Total Error (pix), is the result  satisfying? My Total Error (pix) is 0.97.

Thanks a lot.


Alexey Pasumansky

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Re: Ground Control Points error
« Reply #1 on: January 13, 2017, 07:21:18 PM »
Hello ccrystal98,

The description of the error values is given in the PhotoScan Pro manual. For example, Error (pix) - root mean square reprojection error for the marker calculated over all photos where marker is visible. The values less than 1 pix (or close to that) are usually acceptable. While bigger pixel values for this error usually indicate that either the marker projection is incorrect on one or more photos, or some of the images the marker projection is present on are incorrectly aligned.
Best regards,
Alexey Pasumansky,
Agisoft LLC