This image of a T-38C aircraft in supersonic flight was captured using the sun as a background light source and then processed using NASA-developed code. Researchers have developed new schlieren techniques based on modern image processing methods. This technique requires only simple optics and a bright background that has a speckled appearance, such as the cratered lunar surface or the mottled appearance of the sun when viewed through certain filters. Shock waves, represented by distortions of the background pattern in a series of images, are accentuated using special mathematical equations.