Search Publications
Possible influence of Martian surface mineralogy on the detectability of atmospheric trace gases - mid-infrared simulation results
Błęcka, Maria I.
The paper focuses on the influence of the optical properties of Martian surface minerals on remotely detected gaseous components of the Martian atmosphere, when the spectrometer receives a combined signal from the Martian soil and atmosphere. Our considerations are primarily concerned with the detectability of methane, but the problem may also app…
Performance evaluation of pansharpening for planetary exploration: A case study on the implementation of TGO CaSSIS with MRO HiRISE
Cremonese, G.; Thomas, N.; Re, C. +3 more
The present study analyses the potential of pansharpening algorithms for planetary exploration studies, testing their performance with the 4-band images from the Colour and Stereo Surface Imaging System (CaSSIS) aboard the Exomars 2016 Trace Grace Orbiter (TGO) using HiRISE images from the Mars Reconnaissance Orbiter (MRO) mission as the base. Due…
Insights into the interaction between defrosting seasonal ices and gully activity from CaSSIS and HiRISE observations in Sisyphi Cavi, Mars
Pajola, M.; Munaretto, G.; Vincendon, M. +10 more
Martian gullies are surface features, typically composed of an alcove, a channel and a depositional apron. They have been extensively studied since their first observations in the 2000s and were initially attributed to the action of liquid water. Later studies highlighted that their activity is spatially and temporally correlated with the seasonal…
Targeting and image acquisition of Martian surface features with TGO/CaSSIS
Cremonese, G.; Thomas, N.; Pommerol, A. +12 more
CaSSIS is a high-resolution visual telescope onboard the ExoMars Trace Gas Orbiter. The mission started the primary science phase in April 2018. The relatively small single image footprint (typically 40 km × 9.5 km) when compared to the total surface area of Mars demands that images should be targeted and target selection is key for the science re…
Preface for special issue on the Colour and Stereo Surface Imaging System (CaSSIS) at Mars
Sefton-Nash, Elliot; Wilson, Colin; Hauber, Ernst +2 more
The Colour and Stereo Surface Imaging System (CaSSIS) is the main camera on board the ExoMars Trace Gas Orbiter (TGO). Following launch of TGO on 14 March 2016, CaSSIS began nominal science operations in April 2018. At the time of writing CaSSIS has acquired an average of 21 observations per day, totaling 20.5 Tbits of downlinked telemetry, and ha…
Calibration of NOMAD on ESA's ExoMars Trace Gas Orbiter: Part 1 - The Solar Occultation channel
Vandaele, Ann Carine; Neefs, Eddy; Aoki, Shohei +17 more
Nadir and Occultation for MArs Discovery (NOMAD) is a 3-channel spectrometer suite that is currently orbiting Mars onboard ESA's ExoMars Trace Gas Orbiter, measuring the composition of the Martian atmosphere in unprecedented detail. Of the three channels, two operate in the infrared: the Solar Occultation (SO) channel observes gas species in the 2…
Calibration of the NOMAD-UVIS data
Vandaele, Ann Carine; Neefs, Eddy; Aoki, Shohei +23 more
The Ultraviolet and VIsible Spectrometer (UVIS), covering the 200-650 nm range, is one of three spectrometers that comprise the NOMAD instrument on the ExoMars 2016 Trace Gas Orbiter (TGO). UVIS can operate in solar occultation, nadir and limb viewing mode and was designed to monitor ozone and aerosols in the Martian atmosphere. Here, we describe …
Multiband photometry of Martian Recurring Slope Lineae (RSL) and dust-removed features at Horowitz crater, Mars from TGO/CaSSIS color observations
Pajola, M.; Cremonese, G.; Thomas, N. +12 more
Recurring Slope Lineae (RSL) are narrow, dark streaks typically lengthening down Martian steep slopes during warm seasons, fading during the cold ones and regularly recurring every Martian year. Their origin is still debated. Although initially interpreted as possible flows of seeping water, either coming from a subsurface aquifer or through atmos…
Water vapor saturation and ice cloud occurrence in the atmosphere of Mars
Vandaele, Ann Carine; Aoki, Shohei; Kleinböhl, Armin +3 more
We investigate water vapor saturation in the martian atmosphere in the presence or proximity of water ice clouds. We evaluate mixing ratio profiles of ambient water vapor derived from measurements by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) and the Nadir and Occultation for MArs Discovery (NOMAD) instrument in comparison wi…
Absolute calibration of the Colour and Stereo Surface Imaging System (CaSSIS)
Almeida, Miguel; Cremonese, Gabriele; Thomas, Nicolas +5 more
The Colour and Stereo Surface Imaging System (CaSSIS) onboard the ExoMars Trace Gas Orbiter (TGO) has observed several standard stars and Jupiter with the aim of deriving the absolute calibration factors that convert observed signal into reflectance ("I over F"). The targets were observed through all four colour filters and hence a relative calibr…