UAVs for coastal surveying

UAVs (Unmanned Aerial Vehicles or “drones”) for routine survey applications at the coast have come of age, and are no longer 'the latest thing' more suited to the specialist researcher or amateur enthusiast. Off-the-shelf, survey-grade UAV equipment, data processing and analysis tools are now readily available to practicing coastal engineers, managers and researchers. Within the regulatory constraints that determine their use in many countries, UAVs provide an efficient and cost-effective survey tool for topographic mapping and measurement in the coastal zone. At the practical level, the specialist training required to operate off-the-shelf UAV suited to coastal surveying is now comparable in time and degree of difficulty to learning how to use the equivalent survey capabilities of professional hand-held RTK-GPS equipment. While incremental improvements to both the flight technology and data processing will no doubt continue to occur, from the coastal practitioner's perspective, no more step changes in UAV technology or ease of useability are required. In particular, survey-grade UAVs that incorporate internal RTK-GPS for high accuracy positioning and requiring a single operator only to safely deploy in the field, remove the need for separate and time-consuming on-ground surveying of ground control points (GCPs), previously required during post-deployment data processing. A coastal engineering application of UAV is used here to exemplify the practical use and potential benefits of this now mature survey technology. Over the past 2 years, rapid post-storm deployment of UAV surveying has been successfully integrated into an established coastal monitoring program spanning 4 decades at Narrabeen Beach, Australia. This has extended the scope of this program to include detailed measurements of dune and beachface erosion spanning the full 3.5 km long embayment at a spatial scale and temporal resolution that were previously unfeasible. For both the researcher and practicing coastal engineer, UAVs now provide a practical option for routine coastal surveying.