CCSD3ZF0000100000001NJPL3IF0PDS200000001 = SFDU_LABEL
RECORD_TYPE                    = STREAM
SPACECRAFT_NAME                = GALILEO_ORBITER
INSTRUMENT_NAME                = "NEAR_INFRARED_MAPPING_SPECTROMETER"
INSTRUMENT_ID                  = NIMS
OBJECT                         = TEXT
   NOTE                        = "Description of the NIMS instrument
                                 referenced by EDR and cube labels"
   PUBLICATION_DATE            = 1993-12-15
END_OBJECT                     = TEXT
END

The Near-Infrared Mapping Spectrometer (NIMS) instrument is an imaging
spectrometer covering the wavelength region 0.7 to 5.2 micrometers -- a
region not studied by the Pioneer and Voyager spacecraft.  Its spectral
resolution is 0.025 micron beyond 1 micron, and 0.0125 microns below 1
micron, yielding 204 spectral elements in nominal mode.  The nominal
pixel size is a square 0.5 x 0.5 milliradians.  The instrument acquires
data in the order: (1) sampling of 17 detectors, (2) stepping of the
scan mirror (20 elements in cross-cone), (3) stepping of the grating
(nominally 12 steps per cycle).  The nominal 204 wavelength cycle
requires 4 1/3 seconds.  The detectors (2 silicon, 15 indium antinomide)
sample approximately uniformly across the spectrum.  A detailed
description of the instrument may be found in reference 1.  Earlier
descriptions may be found in references 2 and 3.  An electronic version
of a preprint of reference 1 is available on the NIMS EDR CD-ROMs
in the directory [DOCUMENT.NIMSINST].

The raw instrument data is organized by spacecraft clock.  With a
knowledge of the start and stop time of a given observation, the data
can be organized into a viewable object, normally known as a qube,
stacked images with spatial coordinates on the front and spectral
coordinates along the "back" axis.  The timing of the instrument data
acquisition, with 17 detectors at a grating position sampled at
(nearly) the same time, results in slightly offset geometry for each
grating step.  This is normally adjusted by resampling the data. 

REFERENCES

1.  R. W. Carlson, P. R. Weissman, W. E. Smythe, J. C. Mahoney, and the
NIMS Science and Engineering Teams, "Near-Infrared Mapping Spectrometer
Experiment on Galileo", Space Science Reviews 60, 457-502, 1992.
[This volume also contains papers describing the other Galileo instruments.]

2.  Irving M. Aptaker, "A near-infrared mapping spectrometer for investigation  
of Jupiter and its satellites", SPIE 331 ("Instrumentation in Astronomy IV")
IV", 182-196, 1982.

3.  R. W. Carlson, "Spectral mapping of Jupiter and the Galilean satellites     
in the near infrared", SPIE 268 ("Imaging Spectroscopy"), 29-34, 1981.