This article demonstrates how to track progress over time using drone surveys over a mining site and quickly generate quantity reports and cut/fill maps. Quantity monitoring in mining environments can be simplified by using multiple drone surveys of the same area over time. By having multiple drone surveys quickly accessible in one project, mine managers can obtain additional insight regarding how much dirt was moved within a desired timeframe. This allows better decision-making regarding future work for the mine; the drone data has to be efficiently analyzed to be useful for monitoring the mine.



Overview


Create Timesteps and Organize Your Timeline 

Manage multiple drone surveys over time using the Timeline. 

  1. Create a Timestep for each date the drone is flown over the mine.  
  2. Each drone survey data package—which includes the DSM and orthomosaic—should be imported into the corresponding Timestep. 
  3. Switch from one timestep to another by clicking on the date/name.



Clean the Terrain

Drone data coming from mining operations commonly have many machines (bulldozers, excavators, dump trucks, etc.). You should not include these machines in your volume calculations. To clean the terrain, you can use the Remove Object tool or the Replace Terrain tool.  



To help you detect objects that need to be removed, you can also use the Slope Steepness Terrain Lens. This must be done for each timestep of your drone surveys on the Timeline.


Select the Operation Area

Mines typically cover a large area of land and drone surveys often cover the entire mine.  For your survey, you want to focus on weekly or monthly operations in localized or specific areas. You need to determine the area where you want to calculate your quantity changes. For example, you may focus on blasting areas or excavation zones. Use the Boundary drawing tool to trace the limits of the area you want to focus on. 



This boundary is required for Cut/Fill analysis. If you want to generate an analysis over the whole mine, create a boundary to work in over the entire area.


You can also use multiple boundaries to break up and work on different parts of the mine. See our article Combine Techniques to Survey Large Areas for ideas to help the efficiency of your workflow. 


Create a Cut/Fill Maps

Use the Timeline to switch to the previous drone survey. 

  1. Select the Boundary and go to the TOOLS tab. 
  2. In the Volumes group set the Reference Type to Timestep and select the most recent drone survey as reference for the Cut/Fill calculation within the Reference State box. 
  3. Click on the Cut/Fill button to launch the calculation. 
  4. Cut areas appear in warm colors (yellow to red) and fill areas appear in cool colors (cyan to blue). 
  5. Cut/Fill values for the entire area are available in the Selection box. 



If you have multiple areas of interest, you can select all the boundaries (by holding Ctrl on your keyboard). Cut/Fill calculations are run in parallel, but each area has a dedicated map and quantity result.


See Cut and Fill Over Time

Use the Timeline feature to go through Timesteps and see Cut and Fill values at different points in time through drone datasets.



Create a Cut/Fill Analysis

Now that the Cut/Fill map is available, we can analyze it. 

  1. Select your Cut/Fill map within the Viewport or through the Project View to navigate to the TOOLS tab. 
  2. Set the Min. Cut/Fill value to highlight only significant operation areas. 
    1. Using a 10 cm value typically clears noisy areas. 
  3. Now reduce the stretch value to enhance the color appearance.



It is possible to focus the analysis on one cut or fill area to get quantity results for that specific area. 

  1. Select the Cut/Fill map to get access to the TOOL tab and activate the Extract Cut/Fill area tool. 
  2. Click on the desired area. 
  3. A new Cut/Fill item is created and if selected, related quantities display in the Selection box.



Export Results

If you need to deliver a quantity report, you can export the Cut/Fill analysis results and use these—in third-party software—to present a detailed report. Volume info can be exported as .csv to fill a spreadsheet or as .shp to draw a map. 

  1. Activate all the Cut/Fill items you want to export within the Project View and go to the EXPORT tab. 
  2. In the Cut/Fill group select the export format and click on Export Cut/Fill.


The Selection box also contains a copy icon to copy the information directly to the clipboard.


 

Sample report laid out in Microsoft Word using volume information from the clipboard and a Viewport screenshot: 



Tips and Tricks

You can annotate your Cut and Fill to include values incrementally or show the total volume:

  • Cut and Fill Values spaced out to 15 meters apart.
  • Total Cut and Fill Volume.


It is also possible to export the Cut and Fill in the boundary as a localized image. 

  1. Activate all the items you want to export within the Project View, select a Boundary, and go to the EXPORT tab. 
  2. In the Terrain group, select the export format and click on Export Image.