The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) was a Fourier transform spectrometer for the detection of limb emission spectra in the middle and upper atmosphere on the Envisat mission. It observed a wide spectral interval throughout the mid infrared with high spectral resolution. Operating in a wavelength range from 4.15 microns to 14.6 microns, MIPAS detected and spectrally resolved a large number of emission features of atmospheric minor constituents playing a major role in atmospheric chemistry. Due to its spectral resolution capabilities and low-noise performance, the detected features could be spectroscopically identified and used as input to suitable algorithms for extracting atmospheric concentration profiles of a number of target species.

The full-mission datasets from MIPAS are available from 1 July 2002 (orbit 1746) to 8 April 2012 (orbit 52867). There was an interruption in MIPAS operations in 2004 due to a major anomaly that was resolved at the start of 2005.