THE SPECTROSCOPIC PERFORMANCES OF THE PLANETARY FOURIER SPECTROMETER FOR THE MARS-96 MISSION

The Planetary Fourier Spectrometer (PFS) is a Fourier transform interf erometer, based on a double pendulum concept, which will be part of th e scientific payload of the next Mars '96 space mission. This instrume nt will cover the whole infrared spectral range from 1.2 to 45 mu m, a llowing for the simultaneous measurement of most of the reflected sola r radiation and of the Surface thermal emission from planet Mars. The results of spectroscopic measurements performed by different PFS model s are reported, up to the production of the flight model. The results show the progressive improvement of performances and demonstrate the a ctual spectral capabilities of the last instrument model. Transmittanc e measurements performed by PFS on different gases and liquids show th at the nominal spectral resolution of 2 cm(-1) is actually achieved. T he comparison of the spectra obtained with similar measurements perfor med by a laboratory interferometer clearly show that both strong and w eak features of the samples analysed are well reproduced in position, shape and relative intensity. In conclusion PFS appears a very importa nt tool to study the Martian atmosphere in terms of temperature profil e (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. (C) 1997 Elsevier Science Ltd.