Titan's Surface Composition Investigated by Spectral Mixture Analysis of VIMS/Cassini Data

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

The Visual and Infrared Mapping Spectrometer (VIMS) onboard Cassini and ground-based telescopic observations revealed the diversity of Titan's surface composition. The atmosphere is transparent only in seven narrow ranges of wavelength between 1 and 5 µm, and mixtures of materials certainly occur and distort their absorption bands, even in high spectral resolution measurements. As a consequence, some investigations for specific materials are not fully certain or even failed. In addition, aerosol scattering dominates the signal, especially towards short wavelengths. H2O ice has been reported first by Griffith et al. (2003). Other components are only suggested: CH4 (Coustenis et al. (2005), bitumens and tholins (Lellouch et al., 2004) and CO2 ice (Barnes et al., 2006; Rodriguez et al., 2006) but detection attempt failed for CO2 ice (Hartung et al., 2006).
The global spectral shape also contains useful information to derive the surface composition. Thus, we focused on the analysis of VIMS spectra after averaging the signal within each atmospheric window. Data are selected between 70 degrees emergence angle and incidence angles less than 45 degrees for more homogeneity. We apply a linear spectral unmixing model to fit VIMS data with similarly windowed laboratory spectra of known materials and a model of aerosol scattering. Image fraction maps suggest a major role of CO2 in bright regions like the 5-µm bright spot at Tui Regio (Barnes et al., 2005). Results are consistent with the 5-µm window analysis reported in the companion abstracts (Hayne et al., 2007 and in McCord et al., 2007, this meeting). This analysis is also in agreement with H2O ice at locations previously reported by Soderblom et al. (2007) . Atmospheric scattering is ubiquitous and quite homogenous. This analysis revealed a spectral component bright at 2 µm that may be used to identify other surface components.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Titan's Surface Composition Investigated by Spectral Mixture Analysis of VIMS/Cassini Data does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Titan's Surface Composition Investigated by Spectral Mixture Analysis of VIMS/Cassini Data, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Titan's Surface Composition Investigated by Spectral Mixture Analysis of VIMS/Cassini Data will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1066670

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.