Photogrammetry applied to wind-tunnel testing

In image-based measurements, quantitative image data must be mapped to three-dimensional object space, Analytical photogrammetric methods, which mag be used to accomplish tl,is task, are discussed from the viewpoint of experimental fluid dynamicists. The direct linear transformation (DLT) for camera calibration, used in pressure-sensitive paint, is summarized, An optimization method for camera calibration is developed that can he used to determine the camera calibration parameters, including those describing lens distortion, from a single image. Combined with the DLT method, this method allows a rapid and comprehensive in situ camera calibration and, therefore, is particularly useful for quantitative flow visualization and other measurements such as model attitude and deformation in production wind tunnels. Also included is a brief description of typical photogrammetric applications to temperature- and pressure-sensitive paint measurements and model deformation measurements in wind tunnels.