Fourier phase spectrum estimation using deconvolution from wavefront sensing and bispectrum reconstruction

Abstract

Many techniques for overcoming the optical effects of turbulence have been studied. These correction techniques include post detection image processing, such as speckle imaging (SI) [1] and deconvolution from wavefront sensing (DWFS) [2]. The post detection image processing techniques of speckle imaging and DWFS are of interest because they avoid the investment in expensive and complicated hardware required for adaptive optics. A key factor distinguishing DWFS from SI is that no separate phase spectrum reconstruction step analogous to computing and processing the bispectrum is required in DWFS. We show here that for bright extended objects DWFS provides much better phase spectrum estimation than the bispectrum technique. The qualifier bright is used to describe the case where the object or beacon is bright enough to provide ample signal for low noise wave front estimation using a Hartmann sensor.