Photogrammetry applied to wind-tunnel testing

In image-based measurements, quantitative image data must be mapped to thre e-dimensional object space, Analytical photogrammetric methods, which mag b e used to accomplish tl,is task, are discussed from the viewpoint of experi mental fluid dynamicists. The direct linear transformation (DLT) for camera calibration, used in pressure-sensitive paint, is summarized, An optimizat ion method for camera calibration is developed that can he used to determin e the camera calibration parameters, including those describing lens distor tion, from a single image. Combined with the DLT method, this method allows a rapid and comprehensive in situ camera calibration and, therefore, is pa rticularly useful for quantitative flow visualization and other measurement s such as model attitude and deformation in production wind tunnels. Also i ncluded is a brief description of typical photogrammetric applications to t emperature- and pressure-sensitive paint measurements and model deformation measurements in wind tunnels.