The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) is a Fourier transform spectrometer for the measurement of high-resolution gaseous emission spectra at the Earth's limb. MIPAS was launched on the ESA platform ENVISAT in 2002 and operated until XXX. The MIPAS instrument measured in the near to mid-infrared (4.15 - 14.6 µm) where many of the atmospheric trace gases that play a major role in atmospheric chemistry have important emission features.
Several students and post-docs are engaged in MIPAS projects within AOPP, and there are frequent visits to other European institutes engaged in related work.
AOPP has been involved in the development of the operational processor which is run by ESA to retrieve profiles of temperature and six major species (CH4, H2O,HNO3, N2O, NO2 and O3) in near real time, and has a continued role as an Expert Support Laboratory in order to monitor these results and suggest improvements. In addition, we have developed our own retrieval software with the aim of retrieving the ESA species with improved accuracy (without the constraint of near-real-time processing) and many other species (e.g. SF6, SO2, OCS and NH3) with infrared signatures within the MIPAS spectra. The practical analysis of the large data rate MIPAS signal (approximately 40000 points per spectrum, 17 tangent height spectra per profile) has been achieved by devising the algorithms and creating the software to select spectral microwindows (continuous spectral regions typically less than 1 cm-1 in width). Microwindows are chosen to optimise the information they contain on an atmospheric trace gas for a range of altitudes. A combination of these microwindows are used to determine the entire trace gas profile. This technique reduces the number of data points that need to be processed by a factor of ~100 without significant loss of information (relative to processing all spectra at all measurement altitudes). We also aim to retrieve atmospheric continuum information associated with cloud and aerosols, and use MIPAS data to validate HIRDLS measurements.