A new strategy for deep wide-field high-resolution optical imaging

We propose a new strategy for obtaining enhanced-resolution (FWHM similar or equal to 0 .12) deep optical images over a wide field of view. As is well known, this type of image quality can be obtained in principle simply by fast guiding on a small (D similar to 1.5 m) telescope at a good site, but only for target objects which lie within a limited angular distance around a suitably bright guide star. For high-altitude turbulence this isokinetic angle is approximately 1'. With a 1 degrees field say, one would need to track and correct the motions of thousands of isokinetic patches, yet there are typically too few sufficiently bright guide stars to provide the necessary guiding information. Our proposed solution to these problems has two novel features. The first is to use orthogonal transfer CCD technology to effectively implement a wide-held rubber focal plane detector composed of an array of cells which can be guided independently. The second is to combine measured motions of a set of guide stars made with an array of telescopes to provide the extra information needed to fully determine the deflection field. We discuss the performance, feasibility, and design constraints of a system which would provide the collecting area equivalent to a single 9 m telescope, a 1 degree square field, and FWHM similar or equal to 0 .12 image quality.