LOW COST AERIAL MAPPING WITH CONSUMER-GRADE DRONES

Drones are innovative equipment which are now being used in geographic mapping as an alternative to high cost traditional photogrammetry and ground surveying. Considering the advantages of surveying with drones, pioneering companies in the geomatics industry like senseFly, Trimble, and Leica, etc. have built survey-grade drones specifically for mapping purposes; but in today’s market, there are cheaper consumer-grade drones available. Moving beyond the intentional purpose of these consumer-grade drones, this study was undertaken to identify the potential of using them for mapping purposes. In this study, the Phantom 3 Professional drone was successfully used to map a landscape in Sri Lanka to a horizontal accuracy of 17cm and a vertical accuracy of 28cm. An area of 1.28km was covered by 241 images with an average ground sampling distance of 6.93cm. These high resolution images were processed using Pix4D software to obtain orthoimages and a digital surface model (DSM) of the area. Ground control points surveyed by a differential global navigation satellite system (GNSS) were used to access the accuracy of the products. The results were further compared with a survey-grade drone and other common mapping techniques available today to further understand the benefits and limitations. It was shown that a GPS-enabled consumer-grade drone with an armature camera is a low cost but yet accurate and powerful mapping device which makes it possible to provide necessary aerial maps, DSMs etc. for many applications.