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Imager for Mars Pathfinder (IMP)

NSSDC ID: 1996-068A-01
Mission Name: Mars Pathfinder
Principal Investigator: Dr. Peter H. Smith


The Mars Pathfinder Lander camera is a side-by-side charged-coupled device (CCD) stereo imager in a barrel-shaped housing which sits on top of an extendable mast that stretches 62 cm above its stowed position upon deployment and approximately 150 cm above the surface. There are two 12-position color filter wheels, one in each path of the stereo system. The camera is fully controllable in both elevation and side-to-side (azimuth) motion by stepper motors with gear heads, which provide a field 178 degrees in azimuth and +83 to -72 degrees in elevation. The optics do not require active focusing. The field of view for each eye is 14.4 degrees by 14.0 degrees and the resolution is six-tenths of a millimeter near the lander. The imager is f/18 with a focal length of 2.3 cm. The best focus of the camera is at 1.3 meters, the depth of field ranges from 0.5 m to infinity.

The stereoscopic system consists of 2 eyes covered by fused silica windows separated by 15.0 cm backed by two fold mirrors with one filter wheel and a set of three lenses in each optical path with a fold prism to place the images side-by-side on the CCD focal plane. The two filter wheels contain 24 filters total: fifteen are optimized for Mars geology (four for stereo geology), eight filters for atmospheric and solar studies including four solar filters, and one magnifying diopter filter. The spectral range is 440 to 1000 nm. The spectral channels are particularly sensitive to iron and pyroxene minerals. The CCD is a front-illuminated frame transfer array with 23 micrometer square pixels in two square 256 x 256 pixel frames. Each pixel has an instantaneous field of view of 0.98 milliradian. The signal-to-noise ratio is 350 and both lossy and lossless compressions were used to store and transmit images.

The imager returned 16,661 images, including frames to produce 360 degree panoramas of the landing site. The camera was used for science experiments, including filter-wheel spectral mapping of the landing site to determine the mineralogy of rocks and soil and to identify rocks as targets for further investigation. Spectral mapping was also used to study weathering processes and products in the dust, soil, and rocks of Mars. Images were taken of the surface to study phenomena which occur over time, such as deposition, dune formation and seasonal changes. Images were also taken of the sky, clouds, the Sun, Phobos, Deimos, some stars, and calibration targets on the lander. Frequent images were taken of the rover to support its operations. Two other investigations were associated with the imager. The magnetic properties experiment consisting of five magnets of different strengths was mounted on the lander. Over the course of the mission, images were taken of these magnets to study the accumulation of dust. A wind experiment consisting of three small wind socks mounted on a mast were also the targets of the imager on a regular basis.

Alternate Names

  • IMP
  • Mars Pathfinder Lander Imaging System

Facts in Brief

Mass: 5.2 kg
Power (avg): 2.6 W

Funding Agency

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


  • Planetary Science: Atmospheres
  • Planetary Science: Geology and Geophysics

Additional Information

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



NameRoleOriginal AffiliationE-mail
Dr. Jens Martin KnudsenCo-InvestigatorUniversity of
Dr. Lyn R. DooseCo-InvestigatorUniversity of Arizona 
Dr. Robert B. SingerCo-InvestigatorUniversity of Arizona 
Dr. Horst Uwe KellerCo-InvestigatorMax-Planck-Institut fur
Dr. Lawrence A. SoderblomCo-InvestigatorUS Geological
Dr. Martin G. TomaskoCo-InvestigatorUniversity of
Dr. Peter H. SmithPrincipal InvestigatorUniversity of
Dr. Daniel BrittCo-InvestigatorUniversity of

Selected References

Smith, P. H., et al., The imager for Mars Pathfinder experiment, J. Geophys. Res., 102, No. E2, 4003-4025, Feb. 1997.

Mars Pathfinder, Science, 278, No. 5344, 1734-1742, Dec. 1997.

Smith, P. H., et al., Results from the Mars Pathfinder camera, Science, 278, No. 5344, 1758-1765, Dec. 1997.

Related Information at NSSDCA

Image of Mars Pathfinder Imager on Mast

Mars Pathfinder Imager deployed on the pop-up mast

Mars Pathfinder Images

Other Sources of Mars Pathfinder Imager Data/Information

Mars Pathfinder Imager Home Page (University of Arizona)

Image of the Imager for Mars Pathfinder (IMP) experiment

Imager for Mars Pathfinder (IMP)

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