NASA Photographs Supersonic Schockwaves From Earth; Says You Can Too With Only $3000 Of Consumer Level Gear

Here’s some exciting potential for the astrophotography and/or science enthusiasts out there. NASA has announced they have been experimenting with different types of Schlieren based photography techniques to help them photograph things we typically can’t see, such as air density gradients and, in this case, supersonic schockwaves left behind by a moving aircarft.

“Researchers at Armstrong and NASA…have developed new schlieren techniques based on modern image processing methods. Shock waves, represented by distortions of the background pattern in a series of images, are accentuated using special mathematical equations. This method requires only simple optics and a featured background, that is one with a speckled appearance such as the cratered lunar surface or the mottled appearance of the sun when viewed through certain filters, such as the CaK filter.”

Using the sun as a background (the moon works, too, you just need a bright light source with a speckled surface), the NASA researchers perfectly timed out the image you see above, by photographing the aircraft precisely as it moves past the edge of the sun while moving at supersonic speeds. The image is ran through a series of algorithms as a sort of post production. This technique is referred to as Background-Oriented Schlieren using Celestial Objects, or BOSCO for short.

“Researchers at Armstrong and NASA…have developed new schlieren techniques based on modern image processing methods. Shock waves, represented by distortions of the background pattern in a series of images, are accentuated using special mathematical equations. This method requires only simple optics and a featured background, that is one with a speckled appearance such as the cratered lunar surface or the mottled appearance of the sun when viewed through certain filters, such as the CaK filter.”

There have been several variations of the BOSCO technique, including the one used to take the photos you see in this post. As mentioned by NASA, the addition of a calcium-K optical filter (CaK), allowed the researchers to give the appearance of the sun a more mottled look–a necessary requirement for the Schlieren to work. “Using this naturally speckled background, we could make hundreds of observations of each shockwave, greatly increasing the acuity of the camera system.” NASA is referring to this method as the Calcium-K Eclipse Background Oriented Schlieren, or CaKEBOS.

NASA has been using Schlieren photography for sometime now, but all of their previous successes were achieved as air-to-air photography. Their latest successful attempts, however, were all taken from the ground (ground-to-air), which is quite a breakthrough. This allows the astronauts to more easily photograph moving aircraft and also dramatically reduced the cost of such research by eliminating the need to man a second aircraft from which the photographs would be taken.

In fact, NASA says they used fairly basic astronomy equipment to achieve their results, all of which can be purchased on the consumer market.

Armstrong Flight Research Center principal investigator, Michael Hill noted:

“The CaKEBOS imaging system was very simple, consisting of consumer grade astronomy equipment we had from previous tests. Someone could probably build a system that would get similar results for around $3000.”

If you want to learn more about this fascinating use of photography, you can read NASA’s full post, here.

[ via Engadget | NASA ]