# stockpile measurments

**URL:** <https://community.pix4d.com/t/stockpile-measurments/21171>\
**Category:** PIX4Dmapper\
**Created:** [January 24, 2022, 1:54pm UTC](https://community.pix4d.com/t/stockpile-measurments/21171 "2022-01-24T13:54:12Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![suhaib](https://avatars.discourse-cdn.com/v4/letter/s/e95f7d/32.png) [@suhaib](https://community.pix4d.com/u/suhaib)\
**Post date:** [January 24, 2022, 1:54pm UTC](https://community.pix4d.com/t/stockpile-measurments/21171/1 "2022-01-24T13:54:12Z")

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Hello everyone  
we have a project for stockpile measurements for a land with area equal=0.1 km2  
we will photographed it weekly  
the question is how can I measure the difference volume between two surface and what is the accuracy for this volume?

Thanks

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**Author:** ![Mike\_K](https://sea2.discourse-cdn.com/pix4d/user_avatar/community.pix4d.com/mike_k/32/4697_2.png) [@Mike\_K](https://community.pix4d.com/u/Mike_K)\
**Post date:** [January 24, 2022, 7:02pm UTC](https://community.pix4d.com/t/stockpile-measurments/21171/2 "2022-01-24T19:02:19Z")

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Hi suhaib,  
There are a couple different methods to set your base surface. The article below describes the different vector based surfaces.

> **[Which Base Surface is recommended for the Volume Calculation?](https://support.pix4d.com/hc/en-us/articles/217114246-Which-Base-Surface-is-recommended-for-the-Volume-Calculation)**
>
> Depending on the type of the stockpile that is about to be computed, different options for the base surface are recommended. There are two general categories for the stockpiles:
> 
> Stockpiles whose e...

However if your base surface is a raster then you will want to look at a 3rd party software such as QGIS or ArcGIS to run the calcuations.

As for accuracy, this will come down to your ground sampling distance. Generally, the expected accuracy of a correctly reconstructed and precisely georeferenced project is:

1-2 x GSD horizontally (X,Y coordinates).  
1-3 x GSD vertically (Z coordinate).

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<div class="post-metadata">

**Author:** ![suhaib](https://avatars.discourse-cdn.com/v4/letter/s/e95f7d/32.png) [@suhaib](https://community.pix4d.com/u/suhaib)\
**Post date:** [January 26, 2022, 7:25am UTC](https://community.pix4d.com/t/stockpile-measurments/21171/3 "2022-01-26T07:25:45Z")

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Thanks Mike  
if my GSD=3cm what is that means in volume accuracy?

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**Author:** ![Mike\_K](https://sea2.discourse-cdn.com/pix4d/user_avatar/community.pix4d.com/mike_k/32/4697_2.png) [@Mike\_K](https://community.pix4d.com/u/Mike_K)\
**Post date:** [January 26, 2022, 7:46pm UTC](https://community.pix4d.com/t/stockpile-measurments/21171/4 "2022-01-26T19:46:20Z")

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Generally 3cm GSD is very good. If you are measuring a large stockpile then the error will be very minimal. If you are measuring something that is very small then the error will be greater. How big is your stockpile?

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**Author:** ![suhaib](https://avatars.discourse-cdn.com/v4/letter/s/e95f7d/32.png) [@suhaib](https://community.pix4d.com/u/suhaib)\
**Post date:** [January 31, 2022, 7:16am UTC](https://community.pix4d.com/t/stockpile-measurments/21171/5 "2022-01-31T07:16:42Z")

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Hello mike  
we will photograph the area weekly, so there is a small amount in first photographs I don’t know what is the amount but lets say if its volume about .5 million cubic meter what is the accuracy for this?, and I have another question there is any difference if we use GCPs in calculations?

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**Author:** ![Mike\_K](https://sea2.discourse-cdn.com/pix4d/user_avatar/community.pix4d.com/mike_k/32/4697_2.png) [@Mike\_K](https://community.pix4d.com/u/Mike_K)\
**Post date:** [January 31, 2022, 3:51pm UTC](https://community.pix4d.com/t/stockpile-measurments/21171/6 "2022-01-31T15:51:57Z")

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Hi suhaib,  
Many top mining companies claim that by applying the photogrammetry workflow with Pix4Dmapper, they can achieve measurement accuracies of around 2-5% for their stockpile volumes. This would include the use of GCPs as it will keep both your absolute and relative accuracies as high as possible. I have also attached a PDF that describes how mining companies are using PIX4D for stockpile measurements. I believe this could be helpful for you.  
[BLOG\_drone-mining-stockpile-volume-pix4dmapper.pdf](https://community.pix4d.com/uploads/short-url/kVpBpBYhOEKAaJLTAPzlVm2vtS9.pdf) (475.7 KB)