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Volume Measurement

Currently using a Mavic 2 Zoom to map for measuring material volume in aggregate piles. I have run two maps on normal flight, 80% overlap, and 75ft height, are these optimal settings for accurate volume measurement? On the first map the automated drone control recognized the drone as a Mavic 2 Zoom, the second flight the app recognized the same drone as just a Mavic 2, will this change the outcome?

Kyle Underwood

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80% should be fine for stockpiles. The camera being recognized as different models is a bid... odd. I only see one flight in your uploaded flight data and it says 'Mavic 2 Zoom'. Since you are doing such small areas flying slower will always help your accuracy by minimizing motion blur and it helps to keep the images all captured at the same speed. 

If you are concerned about the data run a subset of it for free and check the overlap in the Overlap Report. You really want the area you care about to all be dark blue in that report. 

When making your measurements use lots of points to define your measurement polygons. 20 points is better than 4. 50 is probably too many.

Zane
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I don't mean to hijack the thread, but concerning:

"When making your measurements use lots of points to define your measurement polygons.."

Zane, you've mentioned this before.  Can you elaborate a bit on this please.  Are the points sampling the elevation of the plane supporting the pile or is there more to it? 

For example, if the supporting plane is entirely flat, why would it make any difference if there are few points?

Dave Pitman 0 votes
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If the plane was entirely flat it wouldn't matter and you could use 4 points. We have found that you get more accurate results with more points because it almost never dead flat. 

Zane 0 votes
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I was using the "entirely flat" example just to get at the mechanics in order to be able to apply a strategy (when needed) to where I place points.  Like when part of the pile toe is covered by vegetation or an adjacent pile. While obviously not ideal situations, I try to skip placing points on those spots if possible electing to place points in spots  more realistically near the ground plane in hopes that the equation is drawing straight lines between points. 

That might make points more sparse in those sections, but it seems to me that would help to make the best of a bad situation accuracy wise.  Does that make sense?

Dave Pitman 0 votes
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