Digital Schlieren Photography

The Holloman High Speed Test Track (HHSTT) currently uses photographic film based image motion compensation techniques to create Focusing Schlieren photos of high speed rocket sleds. Since film processing and film manufacturing continue to be phased out, this capability needs to be replaced by digital cameras. Current state-of-the-art digital cameras are sufficient to replace HHSTT framing cameras, but the Schlieren cameras have several requirements that will require new developments. To obtain Schlieren photography with 0.05 inch spatial resolution a 3000x1 pixel array will be required. To obtain this resolution, on a Mach 10 rocket sled, the exposure time must be no more than ~380ns, resulting in a data acquisition rate of ~8 gigapixels per second. Finally, replacing photographic film also requires development of software to recreate an image from the digitized line-scan data. The overall objective is to develop a Digital Schlieren Camera System to replace film-based techniques to optically record high resolution images of rocket sleds and their test articles at velocities up to 11,000 feet per second. The Phase I goal is to complete the conceptual design of an ultra high speed digital focusing Schlieren camera which can be built and fielded at the HHSTT, in Phase II.