Using a UAV, we take vertical overlapping photographs of the stockpiles. These overlapping photos are then brought into photogrammetric software where 3D models of the stockpile and/or surroUnding area are prepared and volumes determined. UAV-based Aerial surveying allows a rapid cost-effective snapshot of the ground situation at a single instant and is an efficient method for measurement especially when the site is large, there are many stockpiles or there is a large area to measure.
OBTAINING OPTIMUM RESULTS
Aerial surveying from UAVs produce the best results when the stockpiles and surfaces are smooth with well-defined edges. This is because fewer points are required to be measured and it is easier to prepare a 3D model of smooth surfaces.
It is also important to consider the ground surface that the stockpiles sit on. Obviously aerial surveying cannot measure the ground underneath a stockpile, but a smooth base surface for a stockpile will allow more accurate volume determination. Whereas, if the ground beneath the stockpile is irregular or sits partly on a bench or against an irregular wall, surveyors will need to use a best guess estimate of what the ground is doing under the stockpile.