# How to interpret and decrease RMS errors ideal higher the accuracy with GCP's and Geolocation

**URL:** <https://community.pix4d.com/t/how-to-interpret-and-decrease-rms-errors-ideal-higher-the-accuracy-with-gcps-and-geolocation/2803>\
**Category:** PIX4Dmapper Questions/Troubleshooting\
**Created:** [January 12, 2017, 7:20am UTC](https://community.pix4d.com/t/how-to-interpret-and-decrease-rms-errors-ideal-higher-the-accuracy-with-gcps-and-geolocation/2803 "2017-01-12T07:20:01Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Omer\_zubeyr\_Ozerdem](https://avatars.discourse-cdn.com/v4/letter/o/c2a13f/32.png) [@Omer\_zubeyr\_Ozerdem](https://community.pix4d.com/u/Omer_zubeyr_Ozerdem)\
**Post date:** [January 12, 2017, 7:20am UTC](https://community.pix4d.com/t/how-to-interpret-and-decrease-rms-errors-ideal-higher-the-accuracy-with-gcps-and-geolocation/2803/1 "2017-01-12T07:20:01Z")

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Hİ all,

RMS Error, both merged missions optimizing and after step 1 done with the same 528 images is different and high.&nbsp;

RMS error = 0.299 m\>0.289 m

Absolute Geolocation Variance RMS Error [m] 0.907110 1.547622 4.843565\>6.006544 9.344544 2.282369

How is red line polygon area-maybe interested area- erased at north?

Step 2-3 failed.

&nbsp;[Error]: Cannot densify the point cloud! There are 0 points in the densification area!

[Error]: Dense Processing failed!

[Error]: \>\>\>Dense Processing\<\<\< failed with error (No points to densify)!

[Error]: Dense matching failed!

[Error]: \>\>\>Dense matching\<\<\< failed with error (failed to run a step!)!

Best regards

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**Author:** ![Julie\_Pichon](https://sea2.discourse-cdn.com/pix4d/user_avatar/community.pix4d.com/julie_pichon/32/592_2.png) [@Julie\_Pichon](https://community.pix4d.com/u/Julie_Pichon)\
**Post date:** [January 13, 2017, 3:30pm UTC](https://community.pix4d.com/t/how-to-interpret-and-decrease-rms-errors-ideal-higher-the-accuracy-with-gcps-and-geolocation/2803/2 "2017-01-13T15:30:37Z")

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Hi Ömer,

It looks like the images were calibrated at some place but the processing area is somewhere else. For processing step 2, only the points within the processing area are densified. If the processing area is at the wrong place, it fails because there is no points.

We would suggest that you remove the Processing Area using the left side bar of the rayCloud (right click \> Remove) and then draw a new one adjusted to the calibrated cameras at the correct place. More info: [https://support.pix4d.com/hc/en-us/articles/202560179](https://support.pix4d.com/hc/en-us/articles/202560179)

Regards,