| The E-Region Wind Interferometer (ERWIN) is a Michelson interferometer which observes mesospheric winds using Doppler shifts in three airglow emissions (atomic oxygen, molecular oxygen, and hydroxyl). Innovations include a quad mirror and a CCD detector which allow simultaneous observation of winds in four directions and the vertical. A measurement cadence of ~ 3 minutes for all the airglow emissions and directions with an accuracy of ~2m/sis achieved. This is the highest temporal resolution for accurate mesospheric winds in the world, providing the possibility for the first vertical wind measurements in airglow to be achieved. Data analysis algorithms and procedures are developed for this instrument including a Levenberg-Marquardt technique, and a bin-by-bin analysis routine. Interesting geophysical phenomena including a large semidiurnal tide, and significant airglow intensity variations were observed during a sudden stratospheric warming. Comparisons with a meteor radar validate both instruments, and allow the determination of airglow layer heights. |
