Background-Oriented Schlieren Imaging of Supersonic Aircraft in Flight

Abstract

This paper describes the development and use of background-oriented schlieren imaging of a full-scale supersonic jet in flight. A series of flight tests was performed in April 2011, October 2014, February 2015, and December 2018 using the flora of the desert floor in the supersonic flight corridor near the Edwards Air Force Base as a background. Flight planning was designed based on the camera resolution, the mean size and color of the predominant plants, and coordination of several aircraft. Image processing was done with both cross correlation and optical flow algorithms. The planning proved to be effective, and the vast majority of the passes of the target aircraft were successfully recorded. Results were obtained that are the most detailed schlieren imagery of an aircraft in flight to date.