| Summary: | In the field of geosciences and engineering, situations arise where special attention have to be paid to the planning of the UAVphotogrammetric project, that is, terrain with complex geometry and steep slopes. The use of off-nadir imagery and flights at a
fixed height above ground level (AGL) are postulated as possible factors to be considered to achieve high accuracies. The objective
of this study is to evaluate the influence of image angle, frontal and side overlaps, and type of flight (above mean sea level
(AMSL) or AGL), on the accuracy of the dense 3D point cloudyielded by UAV-SfM. The results obtained showed that imagery
with an angle between 20 and 35 in two perpendicular flight line directions, 90/90, 90/70 or 70/70 overlap and AGL flight is
the optimal combination for best accuracy and high precision. With nadir imagery, the combination of factors that gives the
most accuracy results are AGL flights with a 90/70 overlap.
|
|---|