New Outlook on Processing Radiation Received From Objects Viewed Through Randomly Fluctuating Media

A unified approach to interferometry, holography, and the seeing problem is presented. Known interferometric techniques are arranged hierarchically and the concept of the "order" of an interferometer is introduced. When an interferometer is viewing a spatially incoherent object through a randomly fluctuating medium, it is argued that the field of view over which the observed data are isoplanatic depends upon the way in which the data are processed, and the processing methods depend upon the order of the interferometer. By appealing to the principles of Michelson interferometry, intensity interferometry, compound intensity interferometry, off-set holography, and the decomposition of observed radiation into its spatial frequency spectrum, it is found that a convenient characterization can be made of the conditions whereby objects can either be resolved (i.e., the sizes of the objects can be determined) or be imaged faithfully.