Vibration influence research on single camera measurement of angle of attack

A formula for calculating the model angle of attack with the exterior orientation elements of a camera in a single camera measurement of the angle of attack is derived from the collinearity equations which describe the relationship between the image plane coordinates and the physical space coordinates. On the assumption that spanwise coordinate Y of the targets on the model surface keeps constant in a single camera measurement of the angle of attack, the vibration influence on the model angle of attack measurement is investigated in a 2 m wind tunnel when the three angle exterior orientation elements (φ, ω, κ) and model sideslip angle β vibrated between -2° and 2° at five different camera positions. Influence simulation results show that the vibrations of φ and κ have a great influence on the angle of attack measurements, and that the influence is insensitive to the change of camera positions and model angles of attack; the vibration influence of ω and β on the angle of attack measurement is small and negligible when the camera is located at a normal projection position (i.e., the optical axis of the camera is parallel with axis Y), but the influence increases quickly as the camera location moves away from the normal projection position.