Wide-field imaging interferometry testbed (WIIT): image construction algorithms

Abstract

The Wide-Field Imaging Interferometry Testbed (WIIT) is a wide-field spectral imaging Michelson interferometer designed and developed at the NASA/Goddard Space Flight Center. WIIT is now operational and is being used to demonstrate imaging and spectroscopy over fields-of-view larger than the typically narrow primary beam footprint of a conventional Michelson interferometer. At the heart of this technique is the "double-Fourier" approach whereby the apertures and a delay line are both moved to collect interferograms over a 2D wide field detector grid simultaneously; one interferogram per detector pixel. This aggregate set of interferograms, as a function of baseline and delay line, is algorithmically processed to construct a hyperspectral image cube. Herein is developed and discussed the algorithm that constructs the image cube. We show our preliminary results using observed laboratory WIIT data and discuss our ongoing work for image deconvolution.