A fast SWIR imager for observations of transient features in OH airglow

摘要

Since December 2013 the new imaging system FAIM (Fast Airglow IMager) for the study of smaller-scale features (both in space and time) is in routine operation at the NDMC (Network for the Detection of Mesospheric Change) station at DLR (German Aerospace Center) in Oberpfaffenhofen (48.1°?N, 11.3°?E)./br/brCovering the brightest OH vibrational bands between 1 and 1.7?μm, this imaging system can acquire two frames per second. The field of view is approximately 55?km times 60?km at the mesopause heights. A mean spatial resolution of 200?m at a zenith angle of 45° and up to 120?m for zenith conditions are achieved. The observations show a large variety of atmospheric waves./br/brThis paper introduces the instrument and compares the FAIM data with spectrally resolved GRIPS (GRound-based Infrared P-branch Spectrometer) data. In addition, a case study of a breaking gravity wave event, which we assume to be associated with Kelvin–Helmholtz instabilities, is discussed.