Plane Making a Ripple Across the Sun

In the wake of recent success with air-to-air schlieren photography using the speckled desert floor as a background, researchers at NASA’s Armstrong Flight Research Center, Edwards, California, are now looking to the heavens for backgrounds upon which to capture images of supersonic shock waves using ground-based cameras. A bright light source and/or speckled background – such as the sun or moon – is necessary for visualizing aerodynamic flow phenomena generated by aircraft or other objects passing between the observer’s camera and the backdrop. This patent-pending method, made possible by improved image processing technology, is called Background-Oriented Schlieren using Celestial Objects, or BOSCO.
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Patent here actually references what we are seeing in the OP:,599,497.PN.&OS=PN/9,599,497&RS=PN/9,599,497
It has also been contemplated to simply use the edge of the sun as a background for a Schlieren fluid flow analysis of aircraft fluid flow. However, simply using the edge of the sun provides an extremely rough estimate of the fluid flow.
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The idea in the patent is relatively simple:
  • Video the sun with a calcium-K optical filter to get a nice textured image.
  • Stabilize the video
  • Use some kind of change detection algorithm to detect changes between a reference image (a frame of the sun with no plane or shock wave) and each frame of the video.
You could probably do a very simple version of the latter by just subtracting the reference frame from the video frame. We could do this with the OP videos.
We could do this with the OP videos.

Not a huge improvement though. The atmospheric distortion is rippling the image a lot, so you get a flickery ring around the sun.



  • Stabilize motion in Adobe After Effects using the sunspot as a reference point
  • In Photoshop, subtract a still frame from the video
  • Add a levels adjustment to brighten everything up