Research project MO/35/017 (Research action MO)
The purpose of this project is to comprehensively process the stellar/solar occultation and nadir/limb data measured by the SPICAM instrument on board the Mars-Express mission which was successfully placed in Martian orbit in December 2003.
The specific project tasks are as follows:
II Limb and nadir modes
a.Simultaneous UV and IR data will be processed by independent algorithms. For the UV measurement of ozone at nadir, the strong Hartley band should appear on the solar light scattered by the ground and the lower atmosphere as the reflected UV spectrum is the result of light reflected by the surface of a given albedo, Rayleigh scattering by CO2, aerosol/dust reflection and vertical ozone absorption. The SPICAM spectrometer will be regularly calibrated in flight observing standard stars and the Sun whose absolute spectrum outside atmosphere is well known. A (plane-parallel) radiative model will be implemented to fit the total ozone column and the edge of CO2 absorption which is very sensitive to the surface pressure will be used as cross-validation of near IR channel surface pressure measurements.
b. For the retrieval of H2O column in the IR, synthetic spectral of the Martian transmittance will be computed by using the HITRAN-96 database for a multilayered atmospheric model. Results will be cross-compared with those obtained by the IR spectrometer OMEGA on board the Mars Express spacecraft.
c. In the limb mode, nightglow emissions will be processed by using a multiple-scattering radiative code and according to their signal-to-noise ratio both in UV (CO) and in IR (O2) emission bands.
