Multispectral Imagery of Jupiter and Saturn Using Adaptive Optics and Acousto-Optic Tuning

• Published in: Publications of the Astronomical Society of the Pacific Vol. 109; no. 733; pp. 326 - 337
• Main Authors: Glenar, D. A., Hillman, J. J., LeLouarn, M., Fugate, R. Q., Drummond, J. D.
• Format: Journal Article
• Language: English
• Published: American Institute of Physics 01-03-1997
• Subjects: Adaptive optics; Astronomical Instrumentation; Beacons; Cameras; Deformable mirrors; Imaging; Jupiter; Lasers; Saturn; Telescopes; Wavelengths
• ISSN: 0004-6280; 1538-3873
• DOI: 10.1086/133894

We obtained near-infrared, multispectral imagery of Jupiter and Saturn during July 1994 using the second-generation, laser-beacon adaptive optics 1.5-m telescope facility at the USAF Phillips Laboratory Starfire Optical Range (SOR). The telescope optics were equipped with a fast, germanium array and image correlation processor for tip-tilt correction on extended, i.e., planetary objects, and a broadband CCD ''scoring" camera with 0.089 arcsec/pixel sampling, for evaluating the overall system performance. Wavelength tunable imaging was accomplished by sharing the focal plane with a Goddard-built, acousto-optic tunable filter (AOTF) camera operating from 700 to 950 nm. Spectral images of the Jupiter-SL/9 collision sites were photometrically calibrated and reduced to absolute reflectivity (IIF) at each wavelength. Images of the sites show spectrally dependent details which provide the starting point for one-dimensional plume models. Higher quality images of Saturn were acquired, with a spatial resolution of 0.29 arcsec. We attribute this to robust tip-tilt correction made possible by the presence of Saturn's rings, which break the symmetry of an otherwise nearly circular image. The compensated images of Saturn indicate early evidence of a northern hemisphere atmospheric disturbance.