The spectroscopic performances of the Planetary Fourier Spectrometer for the Mars '96 mission

Abstract The Planetary Fourier Spectrometer (PFS) is a Fourier transform interferometer, based on a double pendulum concept, which will be part of the scientific payload of the next Mars '96 space mission. This instrument will cover the whole infrared spectral range from 1.2 to 45 μm, allowing for the simultaneous measurement of most of the reflected solar radiation and of the surface thermal emission from planet Mars. The results of spectroscopic measurements performed by different PFS models are reported, up to the production of the flight model. The results show the progressive improvement of performances and demonstrate the actual spectral capabilities of the last instrument model. Transmittance measurements performed by PFS on different gases and liquids show that the nominal spectral resolution of 2 cm −1 is actually achieved. The comparison of the spectra obtained with similar measurements performed by a laboratory interferometer clearly show that both strong and weak features of the samples analysed are well reproduced in position, shape and relative intensity. In conclusion PFS appears a very important tool to study the Martian atmosphere in terms of temperature profile (by gaseous band inversion methods), vertical distribution of gases and isotopic relative abundance. Furthermore, the PFS performances are suitable for a mineralogical and chemical analysis of solid materials either present on the surface or dispersed in the Martian atmosphere.