Improvements to the sensitivity and sampling capabilities of Doppler Michelson Interferometers
Samuel Kristoffersen, Jeffery Langille, W. E. Ward
Abstract
For the first time, a generalized bin-by-bin analysis approach developed to characterize the visibility, phase, and brightness from Doppler Michelson interferometry (DMI) fringe images is presented. This approach allows for significant advances to the spatial/temporal resolution and sensitivity of DMI utilized for measuring upper atmospheric motions. Expressions for the sensitivity that depend only on the instrument parameters are derived. A unique calibration approach, developed to take full advantage of the DMI imaging capability, is described. The usefulness and validity of this approach is demonstrated using observations from two field-widened interferometers implemented in the field (E-Region Wind Interferometer (ERWIN-II) and the Michelson Interferometer for Airglow Dynamics Imaging (MIADI)). Incorporating the imaging capability into the DMI approach enhances the spatial/temporal information that can be extracted from geophysical observations.