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Using Specular Reflections to Resolve the Degeneracy between Surface and Atmospheric Absorptions. Jason W. Barnes University of Idaho Department of Physics. Cassini Titan Surface Working Meeting 2013 January 30 Tucson, Arizona. A Terrestrial Analog: Beijing, China.
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Using Specular Reflections to Resolve the Degeneracy between Surface and Atmospheric Absorptions Jason W. Barnes University of Idaho Department of Physics Cassini Titan Surface Working Meeting 2013 January 30 Tucson, Arizona
A Terrestrial Analog: Beijing, China
5-micron coadd (16 channels) T85 CM_1721848119
(saturated) T85 CM_1721848119
H2O ice can not be present in abundance: the 2-micron and 2.7-micron spectral shapes are incompatible with Titan's spectrum.
Models from Caitlin Griffith The gap between observed VIMS I/F and atmospheric models show that Titan’s surface reflectance is decreasing from~2.0 to ~2.15 microns
Titan shows interesting spectral diversity in the 5-micron window. From Clark et al., (2010a).
Conclusions: • T85 specular reflection visible at 5um, but also at at 2.8, 2.7, and 2.0um! Not at 1.6 or below. • I used the intensity of the specular reflection as a function of wavelength to infer Titan’s atmospheric transmission at the north pole. Eventually, goal would be to use this to deconvolve surface & atmosphere • So far, optical depth T is about 0.45 higher at 2.7 relative to 2.8 – implies that uncorrected I/F 2.8/2.7um ratios do not constrain surface directly • Can then use this to correct out spectra within each window to reveal slopes, spectral shapes, constraining composition