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measurements taken in this fashion can only be trusted to accuracy on the order of ±5 % chord. Furthermore, IR images are not solely functions of shear stress. Variations in heating or cooling, surface emissivity, internal conduction due to structural members, reflections from nearby hot bodies, and numerous other phenomena introduce significant noise into the IR image. Finally, since each image must be analyzed by hand, a significant amount of time is required to adequately reduce the data from a substantial number of images.As a result of these difficulties, increasing efforts have been made in processing IR thermography in an automated fashion. Raffel and Merz (2014) have developed a technique using differential IR thermography that provides high-contrast images of transition that are well suited for automated processing. In order to generate these highcontrast images, the motion of the transition front is leveraged. However, this is not suitable for analyzing a stationary crossflow-induced transition front where the transition location is quite stable. Additionally, Richter and Schülein (2014) have developed a technique for measuring Tollmien-Schlichting-induced transition on a moving helicopter rotor using IR thermography. This demonstrates one of many scenarios where IR thermography can provide excellent quantitative data, even in a dynamic or otherwise difficult to measure environment. One of the main remaining challenges is the ability to measure transition in a crossflow-dominated environment with the corresponding characteristic sawtooth transition pattern. In a crossflowdominated transition front, the transitional region is a much smaller area and varies strongly as a function of span. This introduces a different set of challenges.The technique described in this article was developed during testing on the SWIFTER (Swept Wing In-Flight Excrescence Research) and SWIFTEST (Swept Wing Abstract A technique for automated, quantitative, global boundary-layer transition detection using IR thermography is developed. Transition data are rigorously mapped onto model coordinates in an automated fashion on moving targets. Statistical analysis of transition data that is robust to environmental contamination is presented.

Experimental techniques for imaging laminar-turbulent transition of boundary layers using IR thermography are presented for both flight and wind tunnel test environments. A brief overview of other transition detection techniques is discussed as motivation. A direct comparison is made between IR thermography and naphthalene flow visualization. A technique for obtaining quantitative transition location is presented.