What is the meaning of RMS Error is this related to respected axis accuracy overall or what? if not than how to check the accuracy of the data?
Hi @himalay24sharma,
Welcome to the Pix4D Community 
.
The mean RMS error you see at the top of your quality report is a mean of the RMS error in the 3 directions (X, Y and Z).
Regarding the Root Mean Square error in each direction, you can find more information here:
I hope this helps you
Cheers
still, I am confused how to check the error of the data or is that RMS error in the report showing error in GCP lying on the ground? than what will be the best option to check the error in the data?
Hi @himalay24sharma,
The RMS will give you the statistical error. If you want to assess the absolute accuracy of the model, you need to use Checkpoints (CP).
You can find more information here:
Thank you Daniele,
While on this topic, can you explain what actual values are used to calculate this reported RMS? I generally calculate my own by placing check points in my mission area if I care enough about actual accuracy, but I’ve always wondered how Pix4D calculates this RMS.
Hi @sunding,
Thank you for your message
This Pix4D Documentation page explains how the RMS is calculated for each direction:
Again, if you want to assess the accuracy of your project, please use checkpoints.
Hello Daniele,
What is the actual measurement between the predicted and observed points in the RMSE calculation? Meaning, the Check Point (CP) is the measured position, what is the predicted position? Is it the nearest point in the point cloud or is it the intersection point in a triangular irregular network?
*observed
…Meaning, the Check Point (CP) is the measured (observed) position, what is the predicted position?..