Adaptive optics are used to compensate
for the atmospheric turbulence
, improving telescope resolution
, which causes twinkling of stars and headache
s to astronomer
Stars are detwinkled by locking onto a nearby, high magnitude star with a known distance. The amount of "twinkle" is then measured by a computer which then sends signals to actuators mounted the telescope's mirror. The actuators finally bend and flex the mirror to remove the greater part of the twinkling. If a convient "guide star" is not available then a laser is projected into the atmosphere at about 50-56 miles up. The computer then locks onto the laser and begins the detwinkling process.
Works on infrared as well as visible light.
Adaptive optics were first developed by the military as a part of the star wars missle defense program. Adaptive optics were meant to help in the sighting of missile trails or warheads moving through space.
Decalassified in 1992, now in use by many professional observatories.