Image registration for Fizeau Fourier transform imaging spectroscopy

Abstract

Fourier transform imaging spectroscopy (FTIS) can be performed with a Fizeau imaging interferometer by recording a series of images with various optical path differences (OPDs) between subapertures of the optical system and postprocessing. The quality of the spectral data is affected by misregistration of the raw image measurements. A Fizeau FTIS system possesses unique degrees of freedom that can be used to facilitate image registration without further complication of the system design. We describe a registration technique based on the fact that certain spatial frequencies of the raw imagery are independent of the OPDs introduced between subapertures. Operational and post-processing tradeoffs associated with this technique are described, and the technique is demonstrated using computer-simulated data with image shift misregistrations under realistic noise conditions.