ATMOSPHERIC-TURBULENCE COMPENSATION BY RESONANT OPTICAL BACKSCATTERING FROM THE SODIUM LAYER IN THE UPPER ATMOSPHERE

A new concept is described for creating artificial beacons for atmospheric-turbulence compensation. A laser tuned to the sodium D2 line is used to excite resonant optical backscattering from the sodium layer in the upper atmosphere. The performance of such a system is compared with that expected from artificial beacons based on Rayleigh scattering in the lower atmosphere. It is found that sodium scattering has a more favorable scaling to large-aperture systems. Applications to the compensation of ground-based astronomical telescopes for atmospheric turbulence are described.

[1]  Freeman J. Dyson.  Image processing and live optics , 1978 .

[2]  Freeman J. Dyson,et al.  Photon noise and atmospheric noise in active optical systems , 1975 .

[3]  A. J. Gibson,et al.  The seasonal variation of the night-time sodium layer , 1971 .

[4]  D. Hunten.  A meteor-ablation model of the sodium and potassium layers , 1981 .

[5]  Nicolaas Bloembergen,et al.  Radiation Damping in Magnetic Resonance Experiments , 1954 .

[6]  J. Grainger,et al.  Anomalous Fraunhofer Line Profiles , 1962, Nature.

[7]  Norman A. Kurnit,et al.  Observation of a Photon Echo , 1964 .

[8]  F. Roesler,et al.  Absorption studies of daytime sodium abundance , 1977 .

[9]  J. Blamont,et al.  The dayglow of the sodium D lines , 1961 .

[10]  D. Hunten.  Surface Albedo and the Filling-In of Fraunhofer Lines in the Day Sky , 1970 .

[11]  Neville J. Woolf,et al.  High Resolution Imaging From the Ground , 1982 .

[12]  B. Clemesha,et al.  The mesospheric sodium layer at 23°S: Nocturnal and seasonal variations , 1978 .

[13]  S. Mccall,et al.  Self-Induced Transparency by Pulsed Coherent Light , 1967 .

[14]  D. Hunten.  Airglow — Introduction and Review , 1971 .

[15]  G. Hernandez.  Reaction broadening of the line profiles of atomic sodium in the night airglow , 1975 .

[16]  B. Clemesha,et al.  Comments on “A meteor-ablation model of the sodium and potassium layers” by D. M. Hunten , 1981 .

[17]  A. J. Gibson,et al.  Atmospheric Sodium measured by a Tuned Laser Radar , 1969, Nature.

[18]  J. W. Hardy,et al.  Active optics: A new technology for the control of light , 1978, Proceedings of the IEEE.

[19]  F. S. Crawford,et al.  Measurement of the size of the isoplanatic patch using a phase-correcting telescope. [for stellar image sharpening , 1979 .

[20]  R. Muller,et al.  Real-time correction of atmospherically degraded telescope images through image sharpening , 1974 .

[21]  J. Blamont,et al.  Laser sounding of atmospheric sodium interpretation in terms of global atmospheric parameters , 1977 .