On the uncertainties in determining fringe phase in Doppler asymmetric spatial heterodyne spectroscopy.

The mean fringe phase measured by Doppler asymmetric spatial heterodyne spectroscopy is a direct measure of atmospheric wind. The uncertainty in measuring the mean phase is investigated and found to be accurately predicted by an analytic formula for moderate and high signal-to-noise ratios. At lower signal-to-noise ratios, numeric issues in the phase calculation result in non-Gaussian distributions of mean phase. Analysis techniques are described to mitigate these numeric issues to the extent possible.