High angular resolution shearing spectroscopy and triple shearing interferometry

Shearing spectroscopy is a new method which can simultaneously yield high spatial and spectral resolution in spite of telescope aberrations and image degradation caused by the atmosphere. Especially attractive is the application of shearing spectroscopy to large astronomical space telescopes. The method is an extension of shearing interferometry. The principle of shearing spectroscopy and laboratory experiments are described. Two different methods have been studied for reconstructing true images and objective prism spectra from shearing data: holographic shearing interferometry, and a new method called triple shearing interferometry. Triple shearing interferometry is in some respects related to the phase closure method in radio interferometry.