Volume measurement with DroneDeploy is an extremely fast, accurate and cost-effective method to analyze volumes on your maps from any device. User tests have found that, when following best practices, DroneDeploy's volume measurements are accurate within 1-2% of traditional ground-based laser measurements.
Below we'll walk you through best practices for how to use the volumetric tool, what the calculations mean, and how to provide feedback.
Adding Volume Capabilities to a Map
Selecting an Area and Measuring its Volume
In order to define a volume to measure, you first need to select an area for which to compute the volume.
- Choose the
Volumeicon from the
Annotation & Measurementoptions:
- Add points around the stockpile for which you want to compute the volume.
- Adjust the points until you are happy with the area of interest. Here is an example result:
- Using the cross arrows in the middle, you can shift the area of interest in order to automatically recalculate the result.
Selecting the Right Base Plane
Choosing the appropriate base plane will help you ensure that you are recording accurate measurements.
There are three base-plane options available for volume calculation; Linear Fit, Lowest Point and Triangulated.
Linear Fit (formerly "Best Fit") defines the base plane by fitting a perfectly flat plane, in 3D, through the chosen edge points. It's great for stand-alone stockpiles in most situations on flat ground.
Lowest Point calculates a horizontal base plane from the lowest edge point. This option is more suited to calculate the volume of benches or stockpiles on flat ground in bins, or where there are neighboring piles right up against each other. The lowest point base plane is very sensitive to the vertices of the volume annotation being created and assumes the ground under the annotation is very flat. If the ground is slightly sloped then, this can distort results.
Triangulated joins up all of the edge points to create a 3D surface under your stockpile. This is perfect for long thin stockpiles, or for large stockpiles over 0.5 acres in size.
Custom Elevation base planes are now available! Simply input the known elevation of the area below the stockpile and the algorithm will do the rest.
Base Plane FAQs
What if I am comparing volume differences over two maps?
Linear Fit baseplanes (and lowest point, triangulated, custom elevation), are all estimations for a baseplane when you have no other data. These baseplanes can vary from map to map with very minor changes, especially if numerous points are selected to outline the stockpile. While these are great for one-off measurements with no other data, they’re not as accurate when comparing maps over time.
We’d recommend updating the baseplane to compare it to an older map, which will use the same polygon with the exact same points and will show the difference between the two volumes, as opposed to using the estimated baseplane.
Measuring on Different Layers
Sometimes it can be difficult to see the base of a stockpile when looking at the Orthomosaic image, due to shadows or similarly colored surrounding areas. To more easily see the nuances in the terrain, we recommend using the Elevation Toolbox as the base layer of the map when computing volumes.
Below is an example that demonstrates why using the Elevation Toolbox is a best practice when calculating volumes. In the Orthomosaic (on the left) it is difficult to see the small pile of rocks to the left of the stockpile. Defining the base layer on top of the small rock pile would lead to inaccurate volume calculations. Using the Elevation Toolbox (on the right), the small pile becomes easily viewable, enabling you to avoid defining a point of the base on top of the rocks.
Creating identical annotations is important for change-over-time mapping. For instance, if you have piles changing on a daily, weekly, or monthly basis you may want to consider copying annotations from map to map. This can be done natively within our app!
How does it work?
- Select the first map and pile you'd like to measure and create your initial measurements. We can think of this as Map #1.
When you fly the site again, you will have a second map that you can now copy annotations to.
Navigate to the map you wish to copy annotations to. In this case, it is Map #2.
Go to Annotations and the option to copy annotations will be at the bottom of the menu.
- You will want to select the annotations that you wish to copy from one map to another. In this case, all annotations have been selected.
- Finally, from the drop-down menu within the Copy Annotations field, select "Copy selected annotations to" and then select the appropriate map date.
Congrats! You have now copied annotations from a previous flight. Now, when you compare those measurements, you will be comparing the same area, location and volume, thus resulting in the most accurate change-over-time calculations!
Understanding the Calculations
The volume calculations between the base-plane and the terrain surface of your area of interest is given in terms of the volume that would need to be removed (in the case of a stockpile) and/or added (in the case of a hole) in order to flatten the surface so that it's the same as the surrounding ground.
Cut vs. Fill
Cut refers to the volume you would have to remove from the area (a pile) in order to flatten it (e.g., you're cutting off the pile).
Fill corresponds to the volume you would have to haul in, to "fill" a hole, in order to flatten the area.
Cut and Fill volumes are automatically shown on the map when calculating volumes. The actual Volume measurement calculation is Volume = Cut - Fill.
Volume Measurements Over Time for GCP Maps
Within DroneDeploy's App Market, you can download the "GCP Volume Analysis" app to see how the volume of your stockpile has changed over time. Simply download the app and then conduct a volume measurement around your stockpile. DroneDeploy will then look for stockpiles in the same area of previous maps that you've flown and show you the Cut, Fill and Volume measurements of that pile. You can even download the data as a CSV file.
For Business and Enterprise customers, you also have access to the Stockpile Report. This will compile your material and volume data in a concise and professional report.
Stockpile AI is a new machine-learning feature that automatically finds stockpile boundaries in your map to save you time.
This feature is available exclusively on our enterprise accounts.
How It Works:
You'll see the new feature in your Annotations section on a recently processed map.
When you select the Stockpile AI button, you'll see outlines of anything we think might be a stockpile.
You can then click on any outline to create an instant (editable) volume measurement.
Repeat steps 2 and 3 for each additional stockpile you want to annotate.
Note: We will often find things that are not stockpiles, so it's up to you to choose to measure the things that are most important.