Sustainable monitoring coverage of unmanned aerial vehicle photogrammetry according to wing type and image resolution.

Unmanned aerial vehicles can collect high-resolution and real-time photos while emitting fewer greenhouse gases than ordinary airplanes and therefore are considered economic and environmentally friendly platforms. However, quantitative analyses of the sustainability of using unmanned aerial vehicles for aerial photography based on their performance and technical constraints compared to that of airplanes are lacking. The purpose of this study is to analyze the economically and environmentally appropriate monitoring coverage of unmanned aerial vehicle photogrammetry according to wing type (such as fixed-wing and rotary-wing types) and desired image resolution (such as 5 cm/pix and 20 cm/pix for the ground sample distance). To determine the sustainable monitoring coverage, the total photogrammetry costs must include the social cost to reduce the emitted greenhouse gases during operation, resulting in a feedback relation. As a result, the sustainable monitoring coverage of fixed-wing unmanned aerial vehicles should be less than 27.50 km2 when the resolution is 5 cm/pix and 30.64 km2 when the resolution is 20 cm/pix. Rotary-wing unmanned aerial vehicles are sustainable when their monitoring coverage is less than 23.98 km2  at a resolution of 5 cm/pix and 26.75 km2  at a resolution of 20 cm/pix. These results provide information on the number of unmanned aerial vehicles and the standing unmanned aerial vehicle deployment plans required to monitor the survey area.