The Process – A small unmanned aerial system (sUAS) is equipped with an inexpensive camera. The area of interest is programmed into the sUAS flight control system and the sUAS automatically flies the area, collecting a large number of overlapping images. Following the flight, a software algorithm is used to generate a dense 3D model from the collected images as well as a mosaic of the images. Finally, an analytic software application is used to compute volumes, generate contours, and create cross sections and other derived data such as gridded elevation models.
Ground Control or RTK Ground Control Points are markers placed on the ground as either permanent marks (recommended for repetitive operations such as quarries) or temporary paint markings. The precise location of these markers is then determined using standard survey techniques. The marks show in the acquired images and are used to provide scale and precise location to the computed models. Alternatively, the drone can be equipped with a survey grade geo-positioning system (Real Time Kinematic, RTK) to significantly reduce the need for ground control.
Collecting Data – The collection of data is accomplished by flying the drone, we recommend a camera-equipped multirotor platform, over the quarry or stockpile site. Under the control of a mission plan uploaded to the drone, the fight is fully automatic. The drone flies a pattern of lines, automatically triggering the camera at the appropriate locations. The drone then self-lands and shuts down.