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Planetary Fourier Spectrometer (PFS)

NSSDCA ID: 2005-045A-04

Mission Name: Venus Express
Principal Investigator:Dr. Vittorio Formisano


The Planetary Fourier Spectrometer is not operational due to the inability to move its pointing mirror assembly into an observing position. The cause of the problem is not known, but no data has been collected so far. Attempts to regain use of the mirror are still being made.

PFS (Planetary Fourier Spectrometer) is an infrared spectrometer that operates in the 0.9 to 45 micron wavelength range and is designed to perform vertical optical sounding of the Venus atmosphere. The scientific objectives are to: perform global, long-term monitoring of the three-dimensional temperature field in the lower atmosphere (from cloud level up to 100 km), measure the concentration and distribution of known minor atmospheric constituents search for unknown atmospheric constituents, determine, from their optical properties, the size, distribution and chemical composition of atmospheric aerosols, investigate the radiation balance of the atmosphere and the influence of aerosols on atmospheric energetics, study global circulation, mesoscale dynamics and wave phenomena, and analyze surface to atmosphere exchange processes

The PFS covers the wavelengths from 0.9 to 45 microns with a spectral resolution of 1.5/cm in two channels, a short wavelength (SW) channel (0.9 - 5 microns) and a long wavelength (LW) channel (5 - 45 microns). The SW channel uses a lead selenide (PbSe)/ lead sulphide (PbS) sandwich photoconducting detector at an operating temperature of 200 - 220 K, a double pendulum interferometer with a calcium flouride (CaF2) beam splitter, and has a field of view of 0.035 radians. The LW channel uses a lithium tantalate (LiTaO3) pyroelectric detector at an operating temperature of 290 K, a double pendulum interferometer with a cesium iodide (CaI) beam splitter, and has a field of view of 0.07 radians.

The collecting optics for both channels are gold coated parabolic mirrors with a focal length of 20 mm, the diameter of the SW channel is 49 mm and the LW channel is 38 mm. The incident radiation is divided into two beams by a dichroic mirror and filtered before being directed into the two channels. The instrument can perform real time Fast Fourier Transforms to select the spectral range of interest for transmission to Earth. The PFS instrument design is based on that flown on Mars Express, modified to optimize performance for the Venus Express mission.

Alternate Names

  • PFS
  • VenusExpress/PFS


  • Planetary Science: Geology and Geophysics

Additional Information

Questions and comments about this experiment can be directed to: Dr. David R. Williams



NameRoleOriginal AffiliationE-mail
Dr. Vittorio FormisanoPrincipal InvestigatorInstituto di Fisica dello Spazio
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