Coastal Shallow-Water Bathymetry Survey through a Drone and Optical Remote Sensors

摘要

Shallow-water bathymetry survey has been conducted using high definition color images obtained at the altitude of 100 m above sea level using a drone.Shallow-water bathymetry data are one of the most important input data for the research of beach erosion problems.Especially,accurate bathymetry data within closure depth are critically important,because most of the interesting phenomena occur in the surf zone.However,it is extremely difficult to obtain accurate bathymetry data due to wave-induced currents and breaking waves in this region.Therefore,optical remote sensing technique using a small drone is considered to be attractive alternative.This paper presents the potential utilization of image processing algorithms using multi-variable linear regression applied to red,green,blue and grey band images for estimating shallow water depth using a drone with HD camera.Optical remote sensing analysis conducted at Wolpo beach showed promising results.Estimated water depths within 5 m showed correlation coefficient of 0.99 and maximum error of 0.2 m compared with water depth surveyed through manual as well as ship-board echo-sounder measurements.