# RMS Error

**URL:** <https://community.pix4d.com/t/rms-error/18330>\
**Category:** PIX4Dmapper Questions/Troubleshooting\
**Created:** [June 1, 2021, 11:09am UTC](https://community.pix4d.com/t/rms-error/18330 "2021-06-01T11:09:08Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![ognjenkralj1](https://avatars.discourse-cdn.com/v4/letter/o/b4bc9f/32.png) [@ognjenkralj1](https://community.pix4d.com/u/ognjenkralj1)\
**Post date:** [June 1, 2021, 11:09am UTC](https://community.pix4d.com/t/rms-error/18330/1 "2021-06-01T11:09:08Z")

</div>

Hi,  
I’ve been doing a road mapping of 2 km long road. I used Pix4dsurvey with very high overlap and a few GCPs (5), DJI Phantom 4 Pro drone.  
After a second step of processing data in pix4d mapper (point cloud and mesh), my quality report showed a red exclamation sign (big rms errors for some GCPs).  
What is the reason for this?

---

<div class="post-metadata">

**Author:** ![Nikoleta\_Dimopoulou](https://avatars.discourse-cdn.com/v4/letter/n/53a042/32.png) [@Nikoleta\_Dimopoulou](https://community.pix4d.com/u/Nikoleta_Dimopoulou)\
**Post date:** [June 1, 2021, 11:13am UTC](https://community.pix4d.com/t/rms-error/18330/2 "2021-06-01T11:13:28Z")

</div>

Hi,

Can you please share with us your quality report?

Best,  
Nikoleta

---

<div class="post-metadata">

**Author:** ![ognjenkralj1](https://avatars.discourse-cdn.com/v4/letter/o/b4bc9f/32.png) [@ognjenkralj1](https://community.pix4d.com/u/ognjenkralj1)\
**Post date:** [June 1, 2021, 12:34pm UTC](https://community.pix4d.com/t/rms-error/18330/3 "2021-06-01T12:34:39Z")

</div>

[M117\_report.pdf](https://community.pix4d.com/uploads/short-url/dA5wfjdPKXMNa0k6yluZuxMPZYy.pdf) (655.7 KB)

---

<div class="post-metadata">

**Author:** ![Daniele\_Lecci](https://sea2.discourse-cdn.com/pix4d/user_avatar/community.pix4d.com/daniele_lecci/32/9493_2.png) [@Daniele\_Lecci](https://community.pix4d.com/u/Daniele_Lecci)\
**Post date:** [June 7, 2021, 10:25am UTC](https://community.pix4d.com/t/rms-error/18330/4 "2021-06-07T10:25:29Z")

</div>

Hi,

Thank you for the Quality Report.  
The error of Ground Control Points (GCPs) is greater than 2 times the Ground Sampling Distance (GSD) may indicate that the GCPs were not correctly integrated into the dataset.

You can find possible causes and suggestions for solutions at this address (please click on **Processing issue / Question \> Step 1. Initial Processing \> Ground Control Points \> High errors in the quality report** ):

> **[Pix4Dmapper guide to troubleshoot issues](https://support.pix4d.com/hc/en-us/articles/360025079672-Pix4Dmapper-guide-to-troubleshoot-issues)**

Please let me know if you find this information helpful.

Cheers