Design and characterization of the balloon-borne Michelson Interferometer for Passive Atmospheric Sounding (MIPAS-B2)

MIPAS-B2 is a balloon-borne limb-emission sounder for atmospheric research. The heart of the instrument is a Fourier spectrometer that covers the mid-infrared spectral range (4-14 microns) and operates at cryogenic temperatures. Essential for this application is the sophisticated line-of-sight stabilization system, which is based on an inertial navigation system and is supplemented with an additional star reference system. The major scientific benefit of the instrument is the simultaneous detection of complete trace gas families in the stratosphere without restrictions concerning the time of day and viewing directions. The specifications, the design considerations, the actual realization of the instrument, and the results of characterization measurements that have been performed are described.

Remote sensing of vertical profiles of atmospheric trace constituents with MlPAS limb-emission spectrometers

A deeper understanding of long-term ozone trends and periods of significant ozone depletion as well as of the anthropogenic greenhouse effect requires the concerted actions of experimenters and modelers. With respect to observations, atmospheric constituents need to be measured simultaneously and on a global basis. Fourier-transform infrared spectrometers are especially suited for this measurement task. Apromising and challenging branch of Fourier-transform infrared spectroscopy is its application to limb-emission sounding by the use of cryogenic instrumentation. This method allows the measurements to be made independently of the time of the day. The MIPAS (Michelson interferometer for passive atmospheric sounding) balloon-borne (MIPAS-B) and space-based (MIPAS-S) experiments apply this technique. While the MIPAS-B instrument has already been used for several years for stratospheric process studies, the MIPAS-S instrument is in development for the European Space Agency's ENVISAT mission. Instrumental aspects of these MIPAS experiments are highlighted, the most important results in ozone research achieved with MIPAS-B are reviewed, and a brief overview of the scientific capabilities of the MIPAS space experiment is given.