16-30 micron spectroscopy of Titan

Titan has been observed from 16 to 30 micron with a resolution of 1 micron. Earlier broad-band data are consistent with the new measurements, which show that the disk integrated flux is nearly constant over the observed range of wavelengths. Limits on the CH4, H2, and N2 column densities and pressures at the bottom of the upper layer are derived. These indicate that if the atmosphere gas is CH4, an H2-CH4 mix, or N2, the inversion layer must be at pressures less than 30 millibars.