INSTRUMENT DESCRIPTION: The following description of SPICAM has been adapted from: Bertaux et al. (2006), SPICAM on Mars Express: Observing modes and overview of UV spectrometer data and scientific results, J. Geophys. Res., 111, E10S90, doi:10.1029/2006JE002690. Korablev et al. (2006), SPICAM IR acousto-optic spectrometer experiment on Mars Express, J. Geophys. Res., 111, E09S03, doi:10.1029/2006JE002696. SPICAM was the first instrument to perform stellar occultations at Mars, and its UV imaging spectrometer (118–320 nm, resolution 1.5 nm) was designed primarily to obtain atmospheric vertical profiles by stellar occultation. The wavelength range was dictated by the strong UV absorption of CO2 (wavelength under 200 nm) and the strong Hartley ozone absorption (220–280 nm). The capacity to orient the spacecraft allows a great versatility of observation modes: nadir and limb viewing (both day and night) and solar and stellar occultations. The SPICAM IR spectrometer on Mars Express mission (1.0–1.7 μm, spectral resolution 0.5–1.2 nm) is one of two channels of SPICAM UV‐IR instrument. In this spectrometer is applied for the first time in planetary research the technology of an acousto‐optic tunable filter (AOTF). SPICAM IR is a point nadir‐looking spectrometer with sequential scanning of the spectrum by the AOTF. Sun occultations are performed with a help of dedicated solar port. A recent review of the 10 years of observations by SPICAM was published by Montmessin et al. (2017), SPICAM on Mars Express: A 10 year in-depth survey of the Martian atmosphere, Icarus 297, pp. 195-216, Article link. User Manual of the service

#Määttänen et al. (2013), A complete climatology of the aerosol vertical distribution on Mars from MEx/SPICAM UV solar occultations, Icarus, 223, doi:10.1016/j.icarus.2012.12.001 #Lebonnois et al. (2006), Vertical distribution of ozone on Mars as measured by SPICAM/Mars Express using stellar occultations, J. Geophys. Res., 111, E09S05, doi:10.1029/2005JE002643 #Forget et al. (2009), Density and temperatures of the upper Martian atmosphere measured by stellar occultations with Mars Express SPICAM, J. Geophys. Res., 114, E01004, doi:10.1029/2008JE003086