*2.2. Image Collection*

This study used a RedEdge 3 camera equipped with a DJI M600 Pro UAV system (SZ DJI Technology Co., Shenzhen, China) to record multispectral images with five bands (Table 1) on 12 September 2018, and 10 April 2019. The camera has a resolution of 1280 × 960 pixels and a lens focal length of 5.5 mm. By using DJI GS Pro 1.0 (version 1.0, SZ DJI Technology Co., Shenzhen, China) software, the overflight speeds were set to 7 m/s and a flight altitude 110 m above ground level. The forward and lateral overlaps were configured to 80% and 79%, respectively, which yielded UAV images with a ground sampling distance of 7.5 cm.


**Table 1.** The band information of RedEdge 3 camera.
