title: Tunable diode laser IR spectrometer for in situ measurements of the gas phase composition and particle size distribution of Titan's atmosphere.
abstract: A new instrument, the Probe Infrared Laser Spectrometer (PIRLS), is described for in situ sensing of the gas composition and particle size distribution of Titan's atmosphere on the NASA/ESA Saturn Orbiter/Titan Probe Cassini Mission. For gas composition measurements, several narrow bandwidth (0.0001 cm(-l)) tunable lead-salt diode lasers operating near 80 K at selected, mid-IR wavelengths (3-16 microm) are directed over a pathlength defined by a small reflector extending over the edge of the probe spacecraft platform; volume mixing ratios of 10(-9) should be measurable for several species of interest. A cloud particle size spectrometer using a diode laser source at 0.78 microm shares the optical path and deployed reflector; a combination of imaging and light scattering techniques will be used to determine sizes of haze and cloud particles and their number density as a function of altitude.
authors.forename: C R
authors.initials: CR
authors.lastname: Webster
authors.forename: S P
authors.initials: SP
authors.lastname: Sander
authors.forename: R
authors.initials: R
authors.lastname: Beer
authors.forename: R D
authors.initials: RD
authors.lastname: May
authors.forename: R G
authors.initials: RG
authors.lastname: Knollenberg
authors.forename: D M
authors.initials: DM
authors.lastname: Hunten
authors.forename: J
authors.initials: J
authors.lastname: Ballard