Accuracy of Drone-Based Surveys: Structured Evaluation of a UAS-Based Land Survey

A recent study concluded that the use of unmanned aerial systems (UAS) could benefit state departments of transportation in four key ways, one of which was the creation of preconstruction surveys. This study investigated whether the use of commercially available UAS and software could create surveys to be used for this purpose. Thirty-one aerial targets were located over a 14,000 m2 site. Half of the targets were used to create the survey and the other half to test accuracy. Two common commercial UAS were used in the experiment. Data were acquired at three altitudes and three separate times. The study found that given the conditions of this experiment, survey points could be within 0.68 cm (0.022 ft) horizontally, 0.09 cm (0.003 ft) in elevation, and 1.46 cm (0.048 ft) in three dimensions (3D) of the true location. The study also found that models created from different images captured at the same altitude had some variability in point locations that ranged from as little as 0.75 cm (0.025 ft) to as much at 3.94 cm (0.129 ft) in the 3D direction.