STELLAR SCINTILLATIONS AS A REMOTE ATMOSPHERIC WAVE-FRONT SENSOR

Stellar scintillations are considered noise in adaptive-optics sensors and are measured for calibration purposes only. We propose to use sci ntillations to provide direct instantaneous information about the stru cture of the atmosphere. As a result it will be possible to increase t he field of view provided by adaptive optics. The scintillation patter n is created when stellar light is diffracted by high-altitude turbule nce. Alternatively, this pattern can be viewed as a Laplacian of this turbulence and can thus be inverted to estimate it. The measurement is limited by the intensity and the angular size of the reference star, by the height distribution of the atmospheric turbulence, and by the d etector resolution and spectral response. (C) 1996 Optical Society of America