Newswise — Twinkling stars and mirages over hot roads are examples of atmospheric turbulence we see every day; the distortion comes from the way light interacts with shifting air. Sometimes turbulence causes the image to appear blurred. Other times it can be like looking at your reflection in rippling water.
Scientists and engineers describe these effects mathematically using what they call blurring functions. When every pixel in an image has the same blurring function, the distortion is said to be “isoplanatic”. In this case the image is just blurred. In the case of the rippling water, different parts of the image are distorted differently. In this case it is “anisoplanatic”
"In my work, I'm looking at the case where every single pixel in an image has a different blurring function," Jeremy Bos says. He calls this “extreme anisoplanatism”.
Bos, an assistant professor of electrical engineering studying atmospheric optics at Michigan Technological University, says the problem is a classic signal-to-noise issue. If the signal is an accurate image, then the distortion caused by turbulence is noise. With enough signal, the image can be recreated: each tipped or tilted pixel in a distorted image can be put back. Bos likens his work to the inverse of the technology used to stream videos online.
"Video encoding technology tries to predict how portions of an image frame change from one frame to another," he says. "In my work, I look at many distorted images of the same scene and try and match each pixel to its true location.”
He adds that clearing up the noise from turbulence will do more than resolve two-dimensional images. It also provides information about the atmosphere as a three-dimensional space. Bos' work in mitigating extreme anisoplanatism will help clear the air.
RSS