MIPAS onboard ENVISAT: preparations for in-flight commissioning and calibration

Abstract

As one of three ENVISAT instruments dedicated for atmospheric chemistry research, the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), a high-resolution Fourier Transform Infrared (FTIR) limb sounding spectrometer, will measure the Earth's limb emission in the infrared range (685 - 2410 cm-1, 14.6 - 4.15 micrometers ) on a global scale over a period of several years. The systematic processing of MIPAS scene and calibration data up to fully calibrated, geo-located limb radiance data and vertical profiles of atomospheric pressure, temperature and volume- mixing-ratios (VMR) of several atmospheric species requires a stable data acquisition and ground processing scenario and a number of calibration and characterization activities prior and after launch. After completion of the Flight Model FM test campaign and subsequent integration and test on the ENVISAT platform, MIPAS is now ready for launch by an ARIANE-5 launcher into an 800 km polar orbit. This paper gives an overview of the MIPAS instrument design, recalls the performance as measured in the instrument ground test campaigns and presents the preparations for the commissioning phase, comprising of an initial switch-on and data acquisition phase (SODAP) and a subsequent calibration/validation (CAL/VAL) phase preparing MIPAS for routine operation.