# Tutorial video how use checkpoint

**URL:** <https://community.pix4d.com/t/tutorial-video-how-use-checkpoint/8629>\
**Category:** PIX4Dmapper Questions/Troubleshooting\
**Created:** [July 4, 2019, 10:05am UTC](https://community.pix4d.com/t/tutorial-video-how-use-checkpoint/8629 "2019-07-04T10:05:42Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Thanh\_Cao](https://sea2.discourse-cdn.com/pix4d/user_avatar/community.pix4d.com/thanh_cao/32/715_2.png) [@Thanh\_Cao](https://community.pix4d.com/u/Thanh_Cao)\
**Post date:** [July 4, 2019, 10:05am UTC](https://community.pix4d.com/t/tutorial-video-how-use-checkpoint/8629/1 "2019-07-04T10:05:42Z")

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Hi Pix4D support team;

I am learning about how to use “checkpoint” to check how accurate products such as Pointcloud, Orthomosaic, DSM,… I have searched the video tutorial on youtube channel [https://www.youtube.com/user/pix4dsoftware/videos](https://www.youtube.com/user/pix4dsoftware/videos) but I don’t see any videos about how to use “checkpoint”. So could you send me instructional videos or any manual&nbsp;documents on how to check products: Pointcloud, Orthomosaic, DSM,…, please?

I have studied some documents about GCP and checkpoint. Then I built the workflow (attached above) on how to use checkpoint to check the accuracy of the products. Could you see it and let me know how accurate is this workflow?[https://drive.google.com/file/d/16WN2dOo348Rkiy4hxhONtYsuOfwMNitG/view?usp=sharing](https://drive.google.com/file/d/16WN2dOo348Rkiy4hxhONtYsuOfwMNitG/view?usp=sharing)&nbsp;

Hope you would try and feedback to me. Thank you!

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**Author:** ![momtanu.chakraborty](https://sea2.discourse-cdn.com/pix4d/user_avatar/community.pix4d.com/momtanu.chakraborty/32/269_2.png) [@momtanu.chakraborty](https://community.pix4d.com/u/momtanu.chakraborty)\
**Post date:** [July 6, 2019, 1:19am UTC](https://community.pix4d.com/t/tutorial-video-how-use-checkpoint/8629/2 "2019-07-06T01:19:51Z")

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Hi Thanh,

The check points are points that are not used as GCPs. They are points with known coordinates that you mark on the images and at the quality report, you check the difference (computed position for the marked points - original position). You can have a look here: [https://community.pix4d.com/t/7177-Using-checkpoints?page=1#community\_comment\_360002939371](https://community.pix4d.com/t/7177-Using-checkpoints?page=1#community_comment_360002939371).&nbsp;Daniel has explained how to use checkpoints. Your workflow looks perfect! This video explains about checkpoints: [https://youtu.be/qeJTbggYwik](https://youtu.be/qeJTbggYwik)