Using Consumer Drones in Surveying Deltas and Coastal Systems

Abstract

Due to rapid developments in the drone industry, low-cost high quality consumer drones are increasingly available to the general public. This research will explore the potential of drones in the field of delta and coastal surveying. Fieldwork was done in Myanmar and involved gathering topographic data to characterize the riverbanks of the Pan Hlaing River. One of the drone-based techniques used is photogrammetry to obtain a digital elevation model (DEM) and Orthomosaic. The other technique is rectification, a process whereby single images are transformed to a 2D map. The research focusses on the methodology of the two techniques, with special emphasis on the use of ground control points (GCP’s), identifying factors determining accuracy and practical challenges in the field. GCP’s derived from satellite imagery were successfully used, with as downside accuracy loss due to satellite map geo-referencing. The root-mean-square error (RMS) was used to identify accuracy. Average accuracy of the rectification end products was in the range of 10 – 40m. Camera lens distortion is identified as a major cause of accuracy loss. Future research should take in account lens distortion changes due to a changing focal distance. Photogrammetry was uncomplicated due to available software for both flying and processing, with the DEM having an accuracy of 1.5m. Further important factors identified to take in account for a successful drone survey are technical capabilities of the equipment used, law, regulation and ethical concerns.