Müller, N. and Helbert, J. and Erard, S. and Piccioni, G. and Drossart, P. and VIRTIS VEX-Team, (2008) Atmospheric correction for VIRTIS VEX images of surface thermal emissions. European Geosciences Union - General Assembly, 2008-04-13 - 2008-04-18, Vienna (Austria).
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Spectral window regions close to 1 micron allow for the transfer of thermal radiation from the surface through the atmosphere of Venus. Results of radiative transfer modeling are used to invert VIRTIS images at 1.02 micron for thermal emission of the surface. Local atmospheric transmittance is derived from the VIRTIS band at 1.31 micron. Statistical analysis of VIRTIS Data allows to empirically find parameters to correct for scattering in the clouds. Thermal emission is dominated by surface temperature which is a function of surface altitude. Comparison of brightness temperature of atmospherically corrected surface emissions with Magellan altimetry indicates extinction in the lowest atmosphere to increase towards the surface. Actual temperature, scattering and absorption properties are not very well known in this layer, and no further correction for these properties is attempted. Instead local deviations of brightness are analyzed by stacking/mosaicking of images and comparison with Magellan SAR images. Tessera terrain frequently is less bright and several lava streams in the lada area show increased brightness.While this might indicate anomalous surface temperature it is unlikely that such temperature not in equilibrium with the average atmosphere persists as observed on timescales longer than days. Surface emissions are expected to be correlated with FeO content of surface material.In conclusion this might indicate tessera terrain to be more felsic and late stage volcanism to be more mafic than the bulk of venusian plains. There are however some reasons to assume that errors in Magellan altimetry become obvious in comparison with VIRTIS images and that tessera terrain more likely induces a systematic offset than other morphological settings.
|Document Type:||Conference or Workshop Item (Poster)|
|Title:||Atmospheric correction for VIRTIS VEX images of surface thermal emissions|
|In ISI Web of Science:||No|
|Series Name:||Geophysical Research Abstracts|
|Keywords:||Venus; thermal radiation of surface; VIRTIS; Magellan; altitude - emissivity - correlation|
|Event Title:||European Geosciences Union - General Assembly|
|Event Location:||Vienna (Austria)|
|Event Type:||international Conference|
|Event Dates:||2008-04-13 - 2008-04-18|
|Organizer:||European Geosciences Union|
|HGF - Research field:||Aeronautics, Space and Transport (old)|
|HGF - Program:||Space (old)|
|HGF - Program Themes:||W EW - Erforschung des Weltraums|
|DLR - Research area:||Space|
|DLR - Program:||W EW - Erforschung des Weltraums|
|DLR - Research theme (Project):||W - Vorhaben Vergleichende Planetologie (old)|
|Institutes and Institutions:||Institute of Planetary Research > Planetary Physics|
|Deposited By:||Stefanie Hempel|
|Deposited On:||29 Apr 2008|
|Last Modified:||27 Apr 2009 14:54|
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