2003-
Spectroscopic Investigation of the Characteristics of the Atmosphere of Mars onboard Mars Express
SPICAM is a space instrument onboard of ESA's mission Mars Express, which has been orbiting around Mars since 2003. The Mars Express satellite was launched on the 2nd June 2003 with a planned operational lifetime of 1 Martian year. SPICAM has been observing since then and is still operating now. The instrument was partly built at BIRA-IASB, in collaboration with the LATMOS (France) and IKI (Russia). It is a double spectrometer composed of an ultraviolet (UV) and a near-infrared (NIR) channel.
The UV channel is mainly used to measure ozone, CO2, and O2 and the NIR channel is used to study water vapor, CO2 and O2. Other components/parameters can be estimated by analysing SPICAM data such as pressure, temperature, aerosols' loading (dust or clouds), surface properties, etc. SPICAM is able to work with different viewing mode, which are Nadir, Limb and solar/stellar occultation. These different viewing modes allow different types of results. For exemple, nadir gives good spatial coverage of the planet and is used to obtain mappings of the studied quantities. Limb or occultations do not have such a good spatial resolution but have the advantage to investigate the atmosphere at different altitudes.
We develop at BIRA-IASB a retrieval algorithm in order to analyse the nadir UV data of SPICAM. The goal is to deduce the quantities of ozone, aerosols' loading and surface albedo. We obtain maps giving the evolution of these quantities over the period of SPICAM activity. We also derive some optical properties of dust in the UV range. This retrieval program is also used to analyse data of the NOMAD instrument which is part of the Trace Gas Orbiter payload.
