1. Sun-view Geometry Causes Hotspot Effect in UAV Imagery During Summer in Tropical Regions

High-resolution imagery acquired by Unmanned Aerial Vehicles (UAVs) is essential for remote sensing applications. However, the high solar elevation around noon during summer in tropical regions produces a hotspot effect when the camera is mapping at nadir. The sun-view alignment generates a bright spot in each image acquired during the flight, which significantly changes the digital number and, consequently, the estimated surface reflectance. The objective of this research was to analyze the presence... W. Maes, L. Rodrigues , A.M. Tommaselli, R.P. Silva, V. Carreira