Two flight campaigns were performed in two different dates, one
with an off-the-shelf DJI Phantom 3 Advanced (Fig. 5) and one with a
custom-made UAV. The custom-made UAV that was used for this
study (Fig. 5) is a hexacopter that bears two camera gimbals. The gimbals
allow for simultaneous capture of the same scene in various angles
depending on the needs of the study. One of the gimbals is generally set
to capture vertical scenes and the other for oblique scenes to realize different
aspects of the same area. The cameras that the gimbals bear are
two GoPro Hero 3+Black Edition action cameras. The RGB GoPro cameras
are capable of capturing photographs at 12MP (3000 pix × 4000