Mining & Construction: Calculating Stock Pile Volumes
Photogrammetry & Drone Technology
Conventionally stockpile volumes are calculated using ground-based surveying methods, requiring the surveyor to physically climb the stock-pile for improved accuracy. In some cases there would be a requirement to close the mine or construction site for days to allow the surveyors to gather data for reporting of stockpile volumes. This presents health and safety risks, high site insurance and plant down time. Typically a ground-based surveyor would measure elevation every 1.5 – 3 meters on each pile. This results in relatively fewer data and inconsistent data points being collected by the surveyor, which inevitably results in inaccurate volumetric calculations.
Lubocon Civils cc; a South African civil engineering operating in the field of major civil engineering projects, was the test ground for stockpile volumetric calculations utilizing drone technology underpinned by photogrammetry software. The objective of this case study was to confirm the benefits of drone technology paired with third-party photogrammetry software in comparison to conventional ground-based Lidar surveying tools. The work scope of the case study comprised of one drone flight over a 644 square meter stockpile and data analysis using third-party photogrammetry software (i.e. DroneDeploy).
Our findings were that to cover a 644 square meter stockpile would take a ground-based surveyor 8 hours vs the 15 minute flight time of the drone. In addition to this we found the following benefits to measuring stockpile using drone and photogrammetry software; i) offer a 3cm variation in cloud points vs 10-20 cm variation of ground-based Lidar ii.) faster reporting within hours of the inspection vs days iii.) safer due to the elimination of the need to climb stockpile.