Who can use this feature
Editors of a project within a Professional or Pro + workspace.
Calculating volume with drone data has a wide array of applications across various industries. In the process of creating your orthomosaic, we also generate a digital surface model and digital terrain model. You can use these to calculate volume in a given area. Some of the common uses include measuring stockpiles of mining materials, determining excavation areas, calculating volume of soil removed or added in land leveling / terracing for agriculture, and assessing erosion and deposition.
To calculate volume on GeoNadir:
Draw a polygon around the area in which you are interested,
Select the polygon in the table of contents,
Use the control (cmd on a Mac) key to multiselect a dataset,
Click the volume tool on the top menu bar (or use the shortcut
shift + v, or access via the toolbox).
After you perform this operation, you will see
A 3D graphical representation of the area you have chosen,
Calculated volume above the base height (see below for how to change) - also known as 'cut',
Calculated volume below the base height - also known as 'fill', and
Net volume.
Interacting with the 3D graph
Click on the graph and use your mouse to move the viewpoint around your graph.
Use the scroll wheel on your mouse to zoom in and out.
Note that the graph is only available when viewing single polygon volumes
Calculating volumes with multiple polygons
1. Select a polygon layer/s or feature/s
2. Hold CTRL (CMD on Mac) and click your dataset so that both layers are selected
3. From the top menu bar, click the calculate volume button (or Shift + V as a shortcut)
4. Review the results in the pop up and optionally change from DSM to DTM and the base height parameter
Exporting results
Simply click on the 'export' button at the bottom of the volume pop up. Your results will start downloading automatically and can be opened in Excel or similar to analyse further
Changing parameters
Elevation model
The volume will be calculated by default using the DSM. You have the option to change this to the DTM instead in the volume pop up.
Base height
The base height is determined by looking at the elevation at each vertex of the polygon, and choosing the lowest value.
You can change this to 'average of polygon vertices'. In this case, the model will look at the elevation at every vertex, and take the average of these values.
Limitations
This tool is fantastic for calculating volumes in relatively small areas of up to 10,000 pixels. The total area that this will cover is variable and will depend on the ground sample distance of each pixel within your dataset.
Note that the accuracy of this tool is dependent on the quality of your input data and the derived DSMs and DTMs. Results will be less accurate where the ground cannot be distinguished in the digital elevation models, such as in areas of dense canopy cover or very large buildings. For best results, use GCPs as part of your processing workflow, and always 'sense check' the outcome.