ABSTRACT Kibblewhite, Edward AST-9421406 Astronomical observations with adaptive optics systems require a detailed understanding of the optical systems and the calibration systematic errors. The Point Spread Function (PSF) affects the signal-to noise ratio and the ability to work in crowded fields. To obtain reasonable (5%) photometric accuracy, either the size of the aperture must be chosen to encircle all the energy within the PSF, negating the effect of the AO system, or a model of the PSF must be used. In addition, the success of deconvolution and the other image enhancing techniques depends greatly on knowledge of the PSF, The program will compare observations of five star fields using the adaptive optics system with a natural reference source with different orders of correction and with a Rayleigh backscattering laser beacon. The five fields of choice are multiple-star systems with separations varying from less than one arcsecond to roughly one arcminute. The PSF will be obtained from the star images in each of the observations. In addition, observations in several bands will illustrate the wavelength dependence of the PSF. Photometric calibration will be made with observations o photometric standard stars. * * *