Application of Unmanned Aerial VehicleeBased Infrared Images in Determining Characteristics of Sea Surface Temperature Distribution

Abstract

This study investigated the temperature field of a body of water by using rotary-wing unmanned aerial vehicles (DJI Mavic 2 Enterprise Dual) comprising visible light and infrared cameras to determine sea temperature distribution. With a flight height of 150 metres, image overlap of 80%, and image resolution of 4.75 cm/pixel, the proposed method was more effective than the conventional portable conductivityetemperatureedepth device in rapidly measuring sea surface temperature and determining sea temperature distribution. The discharged heated water of the Hoping Power Plant traveled 100e330 metres from the wastewater outfall and then gradually diffused in the range of 100e490 metres before reaching a similar temperature to the background sea temperature. The diffusion of the thermal plume was mainly affected by regional marine meteorological conditions.