Data Set Overview
  =================
    The THEMIS IR-EDR data set contains the raw thermal infrared observations
    and their associated calibration images.  Each qube header includes
    basic parameters describing the observation and various telemetry
    information associated with the observation.
 
    The IR-EDR data set is one of several associated data sets included on
    the Mars Odyssey THEMIS Standard Products volume.  These data sets
    include the experimental, reduced, and derived data products.  Each
    observation in the experimental (EDR) and reduced (RDR) data sets is
    stored in a single PDS SPECTRAL_QUBE image product, while each
    observation in the derived (BTR or ABR) data sets is stored in a single
    PDS IMAGE product.
 
    This data set may be reprocessed at the end of the Odyssey mission.
 
 
  Data
  ====
    The THEMIS instrument is a combined thermal infrared (IR) and visible
    (VIS) multispectral, pushbroom imager.  The IR and VIS detector arrays
    are co-aligned, allowing, if desired, the simultaneous observation of the
    same Mars surface location with each detector.
 
    Each image may contain any combination of the available wavelength bands:
    there are ten available bands in the IR detector array, and there are
    five available bands in the VIS detector array.  IR images are 320 pixels
    wide and vary in length from 272 to 65,296 pixels long.  VIS images are
    acquired in framelets of size 1024 pixels wide by 192 pixels long; the
    number of framelets per image is determined by the number of bands
    selected, such that the total image size does not exceed 3.734 Mbytes.
    Spatial summing may be applied after image collection, thereby reducing
    the nominal image dimensions listed above.
 
    All images follow PDS formatting standards and are stored as binary
    images with attached ASCII label and header data objects.  The label of
    THEMIS SPECTRAL_QUBE data products (EDRs and RDRs) contains
    identification and observation parameters associated with the image.
    Also in each header is a HISTORY data object, in ASCII format, detailing
    all processing applied during the generation of the product.  For raw
    infrared (IR EDR) products, the header also includes a second data object
    containing binary telemetry information that was sampled regularly
    throughout the observation.
 
    The application of the THEMIS calibration algorithms transforms a raw
    (EDR) image into a radiometrically calibrated (RDR) image with only minor
    changes to the file format.  Then, the THEMIS derived products are
    calculated from a single band of the corresponding RDR: the infrared
    brightness temperature records (IR BTR) are usually derived from band 9
    (12.57 um); the visible apparent brightness records (VIS ABR) are usually
    derived from band 3 (0.654 um).  The results are stored as an 8-bit IMAGE
    with an attached label containing identification and some basic geometric
    parameters.  For more details of the THEMIS processing algorithms and the
    data product formats, please refer to the Mars Odyssey THEMIS: Data
    Processing User's Guide (CHRISTENSEN2009) and the Mars Odyssey THEMIS:
    Standard Data Products SIS (CHRISTENSEN2014a), included with this data
    set archive.
 
 
  Coordinate System
  =================
    The data products included on the Mars Odyssesy THEMIS Standard Products
    volume are not projected into any coordinate systems.  The image files
    maintain the raw raster order produced by the instrument, reorganized to
    group together the data from each band.  The SPECTRAL_QUBE band are not
    spatially registered.  Layers within a single product can be out of
    registration with each other by up to 10 lines and/or columns.
 
    The geometric parameters stored in the headers of the BTR and ABR IMAGE
    products are generated using the appropriate Odyssey SPICE kernels and
    a THEMIS specific model in the ISIS software.  The values provided
    represent the center of the image and are based on the Mars IAU 2000
    aerocentric model with east positive longitude.
 
 
  Software
  ========
    All data products on this volume follow the PDS standards appropriate for
    the data type, SPECTRAL_QUBE or IMAGE.  Any software tool that
    understands that structure should be able to open and manipulate them.
 
    The THEMIS team uses the software tools DAVINCI and ISIS to display,
    analyze, and project the data products.  DAVINCI is a data analysis
    package for working with multi-spectral images; it is distributed by the
    ASU Mars Space Flight Facility and is available at
    http://davinci.asu.edu.  ISIS is an image processing package produced by
    USGS-Flagstaff and available at http://isis.astrogeology.usgs.gov.
 
 
  Media/Format
  ============
    The publication and distribution of this data set will be facilitated
    online through the THEMIS Data Node (http://static.mars.asu.edu/pds).
    Due to the large volume of data products expected from the mission,
    physical copies of the data will be made for PDS long-term archive
    purposes only.

Please refer to the Mars Odyssey Processing User's Guide
    (CHRISTENSEN2009), which is included with this data set archive.