Studies of Martian Atmosphere and Surface by the Planetary Fourier Spectrometer on Board of the Mars-94 Mission

Kurzfassung

FTIR spectrometry is a powerful tool to investigate the atmosphere and surface composition of planetary bodies. Studies of Mars will provide by the Planetary Fourier Spectrometer (PFS) on board the Mars-94 mission. The PFS mainly focuses on problems of the Martian atmosphere but will give some information of the surface composition as well. Especially for atmospheric observations a high spectral resolution must be required. For analysis of hte Martian ground the signal-to-noise ratio is the most important parameter to be optimised. These conditions define the optical layout of the instument. The presented work discusses the solution for the optical instrument as well as the respected results of PFS remote sensing. The spectrometerconsists of a dual Rotational Reflector Interferometer (RRI) coveringtwo spectral ranges 220 - 1670 cm-1 and 2080 - 8000 cm-1. In the RRI two pairs of retroreflectors, which are connected by L-shaped arms with a common axle, are driven in parallelon a circular path. Partialdeadjustment due to tolerances as well as tolerance effects of real optical elements are taken into account in the estimation of the spectral responsivity in comparison with the radiation of the Martian surface and atmosphere.