Suchergebnisse

NOMAD is a suite of three spectrometers that will be launched in 2016 as part of the joint ESA-Roscosmos ExoMars Trace Gas Orbiter mission. The instrument contains three channels that cover the IR and UV spectral ranges and can perform solar occultation, nadir and limb observations, to detect and map a wide variety of Martian atmospheric gases and trace species. Part I of this work described the models of the UVIS channel; in this second part, we present the optical models representing the two IR channels, SO (Solar Occultation) and LNO (Limb, Nadir and Occultation), and use them to determine signal to noise ratios (SNRs) for many expected observational cases. In solar occultation mode, both the SO and LNO channel exhibit very high SNRs >5000. SNRs of around 100 were found for the LNO channel in nadir mode, depending on the atmospheric conditions, Martian surface properties, and observation geometry. ; NOMAD has been made possible thanks to funding by the Belgian Science Policy Office (BELSPO) and financial and contractual coordination by the ESA Prodex Office. The research was performed as part of the "Interuniversity Attraction Poles" programme financed by the Belgian government (Planet TOPERS). UK funding is acknowledged under the UK Space Agency grant ST/I003061/1. ; Peer Reviewed

NOMAD (Nadir and Occultation for MArs Discovery) is one of the four instruments on board the ExoMars Trace Gas Orbiter, scheduled for launch in March 2016. It consists of a suite of three high-resolution spectrometers - SO (Solar Occultation), LNO (Limb, Nadir and Occultation) and UVIS (Ultraviolet and Visible Spectrometer). Based upon the characteristics of the channels and the values of Signal-to-Noise Ratio obtained from radiometric models discussed in (Vandaele et al., 2015a, 2015b; Thomas et al., 2016), the expected performances of the instrument in terms of sensitivity to detection have been investigated. The analysis led to the determination of detection limits for 18 molecules, namely CO, HO, HDO, CH, CH, CH, HCO, CH, SO, HS, HCl, HCN, HO, NH, NO, NO, OCS, O. NOMAD should have the ability to measure methane concentrations Inter-university Attraction Poles> programme financed by the Belgian Government (Planet TOPERS no P7-15) and a BRAIN Research Grant BR/143/A2/SCOOP. The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement no. 607177 CrossDrive. UK funding is acknowledged under the UK Space Agency Grant ST/I003061/1. ; Peer Reviewed