Introduction
The volume of features can be measured from any geo-referenced raster dataset, orthomosaic dataset, or a digital surface model (DSM).
You can measure the volume of objects on the 2D orthomosaic, on the 2D Digital Surface Model (DSM) or on the 3D point cloud, using the Volume tool in the Annotate/Measure toolbox.
Creating a measurement
Draw a polygon around the feature on the map to calculate and display cut, fill and net volumes in the map.
Base surface
The volume measurement is calculated from a reference surface determined by the polygon surrounding the object you want to measure. The reference surface, called the base surface, can be created in different ways.
There are 3 categories when choosing your base surface:
Quick surfaces generated from the inspected terrain
Previous operation terrain data
CAD overlay
When you want to use an imported DXF file as your base surface, the entities in the DXF have to be 3dfaces. Polyline and point are not supported for volume measurements.
Quick Surfaces
Different types of quick surfaces can be generated from the inspected surface: Interpolated, Flat Minimum Elevation , Flat Maximum Elevation, Flat Custom Elevation.
Interpolated: Selected by default. Connects all the vertices and triangulates the volume above and below the base surface. It uses the z-value at each vertex in your sketch to interpolate a base surface for the volume calculation. Recommended option when the entire boundary of the stockpile is visible and the surface is relatively flat.
Flat Minimum Elevation: The base surface is parallel to the XY plane with altitude at the lowest altitude of all vertices. It uses the minimum z-value found in the sketch vertices to define a flat base surface at the minimum elevation. Recommended option when part of he boundary is not visible, for example the stockpile is partially surrounded by walls.
Flat Maximum Elevation: The base surface is parallel to the XY plane with altitude at the highest altitude of all vertices. It uses the maximum z-value found in the sketch vertices to define a flat base surface at the maximum elevation. Recommended option when the desired computation is the fill volume of a bunker, a pool, a pond, etc.
Flat Custom Elevation: The base surface is parallel to the XY plane with altitude at a custom altitude. It uses the maximum z-value defined by the user. Recommended option when the stockpile is surrounded by walls and only part or even no boundary is visible, but the altitude of the flat base surface is known.
Depending on the type of the stockpile that is about to be computed, different quick surfaces are recommended. There are three general categories for the stockpiles:
Stockpiles whose entire boundary is visible. In this case, it is recommended to select the Interpolated option for the base surface. This option is recommended especially when the terrain around the volume is not flat.
Stockpiles whose boundary is partially visible. The boundaries of a stockpile can be partially or completely hidden by an intersecting stockpile or by walls. In this case, it is recommended to select the Flat Minimum Elevation, if the terrain is flat.
Stockpiles whose boundaries are completely hidden, e.g. in the case of a box full of a material, it is recommended to select the Flat Custom Elevation.
Previous Operations and Overlays
Next to the quick surfaces that generate an artificial surface, you can also use the surface model from a previous operation or from a CAD site overlay.
Take a look at this article to see how you can add overlays to your site.
Cut, Fill and Net volumes
Cut and fill volumes are calculated from the difference between the digitized feature and the defined base surface.
Cut: Ground features above the base surface result in a cut volume. Cut volumes are shown as positive values. The Cut value is the volume removed.
Fill: Ground features below the base surface result in a fill volume. Fill volumes are shown as negative values. The Fill value is the volume added.
Net: The total volume measurement is the net volume, which is calculated by cut volume + fill volume.
Measurement Results
The results from each volume measurement are shown in the measurement feature property box on the platform. When clicking on the specific feature on the map, the feature property box is shown on the map.
The measurements are also compiled in the Measurement Report, which you can download via Export and then selecting Export CSV.