Where the RMSE of Georeferencing is displayed in ArcGIS Pro?

[JamalNUMAN]

Where the RMSE of Georeferencing is displayed in ArcGIS Pro?

I couldn’t figure out where the RMSE of Georeferencing is displayed in ArcGIS Pro.

[SimonWoo]

Sorry, there was a typo in the link.  Let me know if it works now.

[JamalNUMAN]

Still not working!

[SimonWoo]

Overview of georeferencing—ArcGIS Pro | ArcGIS Desktop    

[JamalNUMAN]

Thanks Simon.

Unfortunately, there is no explanation in how the RMSE is calculated. The math and diagrams (pictures) that shows the meaning of RMSE in the geometry is totally absent in the help documents.

In principles, the RMSE refers to the fact that two values are known; the expected and observed. How this can be translated when it comes to the georeferencing? When adding an Image to ArcPro, it is placed in a random place, with georeferencing, a number of points are used to move the image to the correct position. Then where is the expected and observed value in this case?

[SimonWoo]

It is the control points you add that will affect RMSE. 

If you believe that the RMSE is incorrect for your georeferencing, please log an issue or send us your particular case.  

Thanks.

[JamalNUMAN]

Thanks Simon.

Just I wanted to know how the RMSE is calculated mathematically.

In the first screenshot below, the coordinates of the marked point are as shown. With the georeferencing, this point is moved to its correct location. Then what is the meaning of RMSE in this case? Where is the Expected and Observed values in order to be able to calculate the RMSE for this point?

[SimonWoo]

One point is not enough for any RMSE.  You may notice that RMSE is 0, until the 4th control point is created.  It uses these 4 points to figure out what is the expected locations.  And each control point after that is added to the calculation of RMSE.

As mentioned, if you believe that the calculation is not correct, please log an incident and we can take a look.

Thanks!
Simon W

[JamalNUMAN]

I have no particular incident but wanted to know how the RMSE works.

Well, in the screenshot below, the RMSE with a value of 2.10 appears as the 4^th point is added. Then based on what this value is calculated? Where are the expected and observed values in this case that paves the way for the calculation of RMSE?

[SimonWoo]

When Auto-Apply is turned on (which is the default), the image is placed in the "expected" location.  

The point you choose is the actual point (observed).

[JamalNUMAN]

Does this mean that the first 4 points are considered to be the observed based on which all the points on the image map are calculated?

Once the 5^th point is added, then in this case we have two values for it: the one that is calculated (expected) from the first 4 points and the one that is added. The difference is the RMSE.