WFHRI

A New Strategy for Deep Wide-Field High Resolution Optical Imaging.

Nick Kaiser, John Tonry and Gerard Luppino

Artist's impression: click on above image for higher resolution view.

Abstract

We propose a new strategy for obtaining enhanced resolution (FWHM 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 = 1.5m) telescope at a good site, but only for target objects which lie within a limited angular distance of the guide star. For high altitude turbulence this `isokinetic angle' is approximately 1', so one has the problem that with a 1 degree 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 charge-coupled device (OTCCD) technology to effectively implement a wide field '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 on a system which would provide the collecting area equivalent to a single 9m telescope, a 1 degree square field and 0".12 FWHM image quality.

The paper

You can find a paper we have submitted to PASP in paper/ in various formats.

The colloquium

You can watch a colloquium I gave recently to UH physics department in 'real-audio' format.

Animated PSFs

We have generated animated GIF images and MPEG-1 streams showing the evolution of the point spread function for turbulence limited seeing for telescopes of various diameters. These 'movies' may help visualise the properties of PSFs exploited by the WFHRI.