Tracking the 6-DOF Flight Trajectory of Windborne Debris Using Stereophotogrammetry

Numerous post-windstorm investigations have reported that windborne debris can cause costly damage to the envelope of buildings in urban areas under strong winds (e.g., during hurricanes or tornados). Thus, understanding the physics of debris flight is of critical importance. Previously developed numerical models describing debris flight physics have not been validated for the complex urban flow environment; such a validation requires experimentally measuring the debris flight trajectory in wind tunnel tests. In this context, this paper proposes a debris measurement algorithm using stereophotogrammetry. This algorithm aims to determine the six-degree-of-freedom (6-DOF) trajectory and velocity of flying debris, addressing the research gap, i.e., the lack of an algorithm/software for measuring three-rotational-DOF using stereophotogrammetry. This is a civil engineering problem, but computer graphics is the foundation to solve it. This paper focuses on the theoretical development of the algorithm. The developed algorithm can be readily implemented in modern wind tunnel experiments.