NASA Logo, National Aeronautics and Space Administration
NASA Space Science Data Coordinated Archive Header

Mars Atmospheric Water Detector (MAWD)

NSSDCA ID: 1975-075A-03

Mission Name: Viking 1 Orbiter
Principal Investigator:Dr. Crofton B. Farmer


The MAWD used an infrared grating spectrometer mounted on the orbiter scan platform that was boresighted with the television cameras and the IRTM. The instrument measured solar infrared radiation reflected from the surface through the atmosphere to the spacecraft. Spectral intervals were selected coincident with the wavelength of water-vapor absorption lines in the 1.4-micrometer band. The quantity of water vapor along the line of sight was measured from 1 to 100 micrometers of precipitable water with an accuracy of 5% or better. The instantaneous field of view of the instrument was 2 x 17 milliradians, and a stepping mirror rotated the line of sight through 15 positions to provide a roughly rectangular field of view of 17 x 31 milliradians. Operation of this experiment was terminated on August 7, 1980.

Alternate Names

  • Infrared Spectrometer Specific for Water
  • MAWD
  • Viking1Orbiter/MAWD
  • urn:nasa:pds:context:instrument:mawd.vo1

Funding Agency

  • NASA-Office of Space Science Applications (United States)


  • Planetary Science: Atmospheres
  • 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. Crofton B. FarmerTeam LeaderNASA Jet Propulsion
Mr. Dan LaporteTeam MemberSanta Barbara Research Center
Dr. Donald W. DaviesTeam MemberNASA Jet Propulsion

Selected References

  • Farmer, C. B., and D. D. Laporte, The detection and mapping of water vapor in the Martian atmosphere, Icarus, 16, No. 1 34-46, doi:10.1016/0019-1035(72)90135-2, Feb. 1972.
  • Farmer, C. B., et al., Viking - Mars atmospheric water vapor mapping experiment - preliminary report of results, Science, 193, 776-780, doi:10.1126/science.193.4255.776, Aug. 1976.
  • Davies, D. W., et al., Behavior of volatiles in Mars' polar areas - a model incorporating new experimental data, J. Geophys. Res., 82, No. 26, 3815-3822, doi:10.1029/JB082i026p03815, Sept. 1977.
  • Jakosky, B. M., et al., The observed day-to-day variability of Mars atmospheric water vapor, Icarus, 73, No. 1, 80-90, doi:10.1016/0019-1035(88)90086-3, Jan. 1988.
  • Farmer, C. B., et al., Mars: Water vapor observations from the Viking Orbiters, J. Geophys. Res., 82, No. 28, 4225-4248, doi:10.1029/JS082i028p04225, Sept. 1977.
  • Jakosky, B. M., and C. B. Farmer, The seasonal and global behavior of water vapor in the Mars atmosphere: Complete global results of the Viking Atmospheric Water Detection Experiment, J. Geophys. Res., 87, No. B4, 2999-3019, doi:10.1029/JB087iB04p02999, Apr. 1982.
[] NASA Logo -