Planetary Fourier Spectrometer

At this point, it is also appropriate to mention the Composite Infrared Spectrometer (CIRS) on the Cassini spacecraft, that flew past Jupiter in December 2000 and will arrive at Saturn in July 2004, and the Planetary Fourier Spectrometer (PFS) on the Mars Express spacecraft, to arrive at Mars in December 2003. Both spectrometers are dual channel instruments consisting of short- and long-wave interferometers. First, we discuss CIRS. 

From the late 1950s onward, Venus has been subjected to a variety of increasingly sophisticated Earth-based, Earth-orbital, and spacecraft observations. Spectroscopic observations of Venus were carried out using high-altitude telescopes carried on balloons or on airplanes. Fourier transform infrared (FTIR) spectrometers were applied to planetary spectroscopy and were used to observe Venus. As a result, the and... 

The retrieval method has been used extensively for temperature profile retrieval in both the terrestrial and other planetary atmospheres. Examples of profiles obtained by this technique for Earth, Mars, Jupiter, Saturn, Uranus, and Neptune are shown in Fig. 8.2.2. Also included is a Titan profile obtained from radio occultation data. The profiles for Earth and Mars were derived from measurements obtained with the Fourier transform spectrometers carried on Nimbus 3, 4, and Mariner 9, respectively. In both cases data from the 15 ptm. CO2 absorption band were used. The profiles for the outer planets were obtained by inversion of measurements from the Voyager Fourier transform spectrometers. For Jupiter and Saturn, data from the S(0) and S(l) collision-induced H2 lines between 200 and 600 cm were used, along with measurements from the CH4 V4-band centered near 1300 cm . Because of the extremely low temperatures encountered on Uranus and Neptune, adequate signal-to-noise ratio for the retrieval of vertical thermal stmctures was obtained... 

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