Correction of the aberrations of space-based telescopes using intensity functionals and detection cells with dimensions exceeding the focal spot

The correction of the aberrations of space-based telescopes using functiona ls of the recorded intensity for dimensions of the cells in the CCD array s ensor exceeding the ideal focal spot is considered. The correction quality for short and long exposure times is analyzed with allowance for the residu al tracking error of the telescope. It is shown that the inclusion of a sta ge of preliminary weak defocusing of the radiation is required to achieve h ighly accurate correction in adaptive optical systems. (C) 2000 The Optical Society of America.