Lucky Imaging - History

History

Lucky imaging methods were first used in the middle 20th century, and became popular for imaging planets in the 1950s and 1960s (using cine cameras, often with image intensifiers). For the most part it took 30 years for the separate imaging technologies to be perfected for this counter-intuitive imaging technology to become practical. The first numerical calculation of the probability of obtaining lucky exposures was an article by David L. Fried in 1978.

In early applications of lucky imaging, it was generally assumed that the atmosphere "smeared-out" or "blurred" the astronomical images. In this work, the FWHM of the blurring was estimated, and used to select exposures. Later studies took advantage of the fact that the atmosphere does not "blur" astronomical images, but generally produces multiple sharp copies of the image (the point spread function has "speckles"). New methods were used which took advantage of this to produce much higher quality images than had been obtained assuming the image to be "smeared".

In the early years of the 21st century, it was realised that turbulent intermittency (and the fluctuations in Astronomical seeing conditions it produced) could substantially increase the probability of obtaining a "lucky exposure" for given average astronomical seeing conditions. .