Click the model above to view the high resolution 3D stockpile created using nadir and oblique imagery

Actionable Data: Stockpile Volume Measurement Case Study Results

UAV Stockpile Volume Results

The image to the left shows the final rendering of the stockpile using UAV imagery after software processing.

Total volume = 71.83 m3

Click image to enlarge

Survey Stockpile Volume Results

The image to the left shows the final rendering of the stockpile using conventional survey methods

Total volume = 73.242 m3

Click image to enlarge

UAV Stockpile Volume Case Study Results

The flight mission and case study started with setting up and surveying the stockpile. The surveyor captured several points around the base of the stockpile, following the shape, and points along the top and sides of the stockpile as well. Care was taken to follow all contours (highs and lows) of the stockpile to get the most accurate measurement possible.

Once the stockpile survey was complete, we followed our protocols to complete a UAV aerial mapping mission to capture nadir and oblique imagery for point cloud, 3D mesh, orthomosaic and digital surface model (DSM) generation. A total of 158 photos were captured, and 120 photos were used to generate the results. Average ground sampling distance (GSD) is 0.17 cm/pixel. This UAV flight mission was completed in manual mode.

 Survey Stockpile Volume

73.242 m3

 UAV Stockpile Volume

71.83 m3

Calculations

Difference:  1.412 m3
Variance: 0.9968

As you can see with the results above there is about a 1.9% difference between the surveyed stockpile volume and the UAV stockpile volume.  One important point to keep in mind is that the UAV stockpile volume is less than the survey stockpile volume.  This is important because the surveyor took care to ensure to capture the outer extents of the stockpile in 3D space.  If the UAV stockpile volume was greater, there would be obvious error.

This case study shows that using unmanned aerial vehicles to measure stockpile volumes is feasible.

Why Use Unmanned Aerial Vehicles for Stockpile Volume Measurements

Safety

One of the primary reasons to use unmanned aerial vehicles to calculate stockpile volumes is safety.  Walking on stockpiles can be dangerous for ground personnel.  The type of material, how high it is stacked and features of the pile, including drop-offs and overhangs can greatly increase the risk of injury for ground personnel.  Unmanned aerial vehicles mitigate the risk, completely.

Speed

While set-up times for survey and UAV missions are close to the same, completing the stockpile survey with unmanned aerial vehicles is much quicker.  An area of 1 hectare, capturing nadir and oblique imagery can be completed in 20 to 30 minutes.  Detailed, or higher resolution missions take between 30 minutes and one hour.

Accuracy

The case study above shows that unmanned aerial vehicles can measure stockpile volumes with a great deal of accuracy.  The UAV imagery captures every aspect of the stockpile, all of the highs and lows and all of the curves; nothing is left out.

Benefits of UAV’s for Stockpile Measurement

  • Safety
  • Speed
  • Accuracy
  • Actionable Data

UAV’s in Civil Construction

This case study is just one example of how unmanned aerial vehicles can be used for practical applications in the construction industry.  Some other considerations include construction planning, construction monitoring, through all phases of a project and inspections.  Please Contact Us to find out how we can help with your civil construction needs.

Additional Media

Well Graded Base (WGB) Stockpile

Volume: 4665.28 m3

Measure stockpiles, even if they are placed up against a slope

Screened Rock/Pit Run

Volume: 901.49 m3

Measure complex surfaces.  Please note that voids within the stockpile are not accounted for within the volume.

UAV Flight Mission

  • Coordinates: not posted
  • Airspace Classification: G
  • Flight Difficulty Level: Advanced
  • Obstacles: Trees, Terrain
  • Hazards: Manned Aircraft, Vegetation, Wind, Wildlife

Airspace Classification

The subject property is located outside the 9.0 Km radius of the Kamloops – CYKA – FSS, Clearwater and Shuswap aerodromes.  Unmanned Aerial Vehicle / Drone flight missions were conducted following protocols for Class G airspace as outlined in the Canadian Aviation Regulations to fly at this location.  Please reference the Canadian Aviation Regulations and see our UAV Regulations page for more information.

Unmanned aerial vehicle flight missions at this location require special considerations.  Permission was granted by the Client to conduct unmanned aerial vehicle flights at this location.  Safety considerations included monitoring for manned aircraft and heavy equipment working in the area.  Our visual observer ensured our UAV stayed within line of site and also assisted with sense and avoid situations.  Privacy of local landowners was also considered and respected.