Comparing surfaces and creating volume measurements are key components to effectively analyze your site. The Surface Comparison tool allows you to designate an area using the polygon tool, and then compare drone surveys, design files, and a variety of other surfaces in the platform.
Use cases
- Measure stockpiled material on an uneven surface using a previous flight, imported design, or interpolated surface as the base
- Measure earthworks progress
- Measure landfill cell conformance to design
- Create dynamic cut/fill or takeoff maps
Types of volume measurements
Area Progress: Measure site progress from the previous survey against an uploaded design surface.
Bench Volume: Measure the volume of wall or bench section. This is useful for measuring blast volumes.
Cut/Fill: Measure progress or change in volume between your selected survey and your previous site survey.
Stockpile: Measures a stockpile using a smart, reference level, or custom base. Use the Stockpile Measurement template to create customized Stockpile Inventory Reports.
Polygon: Measures your choice of custom items in a drawn polygon.
Surface Area: Measures the surface area within a polygon.
Custom: You can create custom measurements to suit your specific needs.
How to create a measurement
Pick the measurement type (Point, Line, or Polygon) from the toolbar.
From the measurement toolbar, select Polygon. Choose a template from the dropdown menu.
Use the Magic Polygon tool or manually draw a polygon around the area you want to measure.
Select the surfaces you want to compare in the From and To Surface dropdown menus.
Select the surfaces you want to compare in the From and To Surface dropdown menus.
Change measurement units
Select the most appropriate measurement unit for distance, area, volume, and density from the dropdown menu. This makes it easy to move between imperial and metric units as needed and create reports in your preferred units.
How to compare one dataset or design to another
Select the appropriate polygon tool from the dropdown menu.
Use the Magic Polygon tool or draw a polygon around the area of interest.
If you choose the Area Progress option, the To Surface will already be populated with the current survey. In the From Surface option, pick what you want to compare.
You can always switch between the From Surface and To Surface comparison calculation by clicking the arrows between the two surfaces.
When comparing surveys, they must overlap with the current measurement to calculate data.
When comparing surveys, keep in mind the following:
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When comparing a current dataset to an older dataset, the FILL value is the volume added to the selected area, and the CUT value is the volume that has been removed. If the amount of material in the region has increased, the NET volume is shown as positive.
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This can be visualized using a heat map to highlight cut and fill areas, as seen below. The dark red areas are mounds of stockpiled fill flattened in the period between datasets. The blue areas are being filled to reach design level conformance, while uncolored areas have minimal changes in the period between the two datasets.
+ADD/EDIT ITEMS
To customize the measurement you create further, click +ADD/EDIT ITEMS and select the available tools from the list.
Customize options
General items
- Description
- Dropdown list
Measurement items
Horizontal Area calculates how much earth needs to be leveled or graded.
Vertex Elevation defines how much earth needs to be moved to achieve a desired surface shape.
Surface Area is a calculation that helps determine the volume of materials to be removed (cut) or added (fill).
Remaining to Design helps determine the exact amount of material that needs to be removed (cut) or added (fill) to achieve the final design specifications.
Material Properties is information on material density and value.
Surface Comparisons calculates cut and fill volumes during excavation or grading projects.
How do I account for shrink and swell?
Shrink/swell describes how soil or material changes in volume when excavated (cut) or compacted (fill). Accurately calculating shrink and swell factors is critical for cost estimation, logistics, and planning in earthwork projects.
Shrink refers to the reduced volume of soil or material after it is excavated, transported, and compacted in a fill area.
Swell refers to the increase in volume of material when it is excavated from its original, natural state.
Enter the shrink-swell factor for the cut and fill to calculate the Cut, Fill, Net, and Total volumes. For example, if your swell factor is 5%, input 1.05. If your shrink factor is 5%, enter 0.95.
When applied to cut or fill, a factor >1 is needed for swell and a factor <1 is needed for shrink.
You can also export shrink/swell factors and the adjusted cut/fill values in stockpile reports.
How do I use the deadband in volume comparison measurements?
Users can set a deadband for their measurements using the volume comparison tool. This deadband will ignore surface changes less than the minimum value set for the heatmap and will not contribute any of those changes to the CUT/FILL/NET/Total values generated for that measurement.
To enable the deadband for your volume comparison measurement, scroll down below the CUT/FILL/NET/Total numbers to the Heatmap section of the measurement, and check the box for Use deadband in the calculation. Then, you must apply that change by clicking APPLY at the bottom of the measurement.
You will see an information box alerting you the deadband has been applied successfully.
As a default for drone survey comparisons, the minimum value is 0.1ft (3 cm) in Imperial units, and 0.1m (10 cm) in Metric units. However, the Deadband is not enabled automatically.
Using DirtMate data in volume comparison measurements
The deadband of 0.1ft (3 cm) or 0.1m (10 cm) is automatically applied on measurement creation when DirtMate layers are toggled on. If the deadband is not applied, you will see a message with a link to APPLY DEFAULT. Please get in touch with our Site Support team for questions about the deadband when applied to DirtMate measurements.
I still can't do it!
We wrote these articles to equip you with everything you need to get the job done on your own, but we understand that sometimes this isn't sufficient.
If you're stuck, you can connect with our support team by clicking the support button on the top right corner of your user portal.
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