Data Set Overview
    =================
 
    This data set contains calibrated spectra from Near
    Infrared Spectrometer #2 on the LCROSS spacecraft.  During the
    final moments of the LCROSS mission, NSP2 looked toward
    the sun to capture absorption spectra as the spacecraft
    passed through the ejecta and vapor cloud left by the
    centaur impact.
 
    Each file in this dataset contains a 100 pixel spectra
    in an ascii, single-column, tabular format.  All spectra
    in this dataset used an integration time of 0.5 sec.
    The spectrometer's field of view was circular and 1 deg
    in diameter.
 
    All spectra in this dataset have the sun as their
    target, although it is outside the instrument's field of
    view during some calibration data collection periods.
 
    The time each spectra was captured is encoded in the
    spectra's filename like this:
 
      LCROSS_NSP2_CAL_.IMG
 
    where  = YYYYMMDDHHMMSSmmm
      and YYYY = the four digit year;
          MM = the two digit month,
          DD = the two digit day, and so on
          through hours, minutes, seconds and milliseconds.
 
    The detached label for each spectra has the same
    filename as the spectra but with the 'LBL' extension.
 
    This dataset encompasses all calibrated spectra
    collected by NSP2 during the mission, however, the
    archive's DATA directory is partitioned initially by
    payload data collection period.  The data collection
    period called 20091009113022_IMPACT contains the data
    from one minute prior to the Centaur impact through the
    end of the mission.  Other data collection periods
    periods contain data from various calibration targets.
 
    Related Data Sets
    =================
 
    This dataset is closely related to the NSP2_PREHAD and
    NSP2_RAW datasets.  This spectrometer transmits data
    through the spacecraft to the ground in a format that is
    processed to create these raw spectra.  The processing
    algorithm is a kind of Fourier transform called a
    Hadamard transform.  The pre-Hadamard data for this
    spectrometer is contained in a dataset described in
    NSP2_PREHAD_DS.CAT in this directory.  This algorithm is
    deterministic and has no inputs other than the
    pre-hadamard data, so reprocessing that data to generate
    updated raw spectra is unlikely.  However, the
    pre-hadamard data is used to determine whether spectra
    contain saturated pixels.
 
    This dataset is not as closely related to NSP1_RAW and
    NSP1_CAL.  Unlike the camera pairs which had overlapping
    fields of view, NSP1 and NSP2 were pointed in different
    directions.  NSP1 was pointed downward, toward the
    centaur impact, while NSP2 was pointed toward the sun to
    measure absorption spectra.
 
    Parameters
    ==========
 
       Science
       -------
 
       No instrument parameters vary within this dataset.
       The integration time is uniformly 0.5 seconds.
 
       Housekeeping
       ------------
 
       Instrument temperature at the data collection time is
       reported in the label file under
       INSTRUMENT_TEMPERATURE and
       INSTRUMENT_TEMPERATURE_COUNT in degrees Centigrade
       and raw counts, respectively.  This is a single
       telemetry point most representative of the
       instrument chassis temperature.
 
    Processing
    ==========
 
    Each near-infrared spectra was digitally transmitted
    from the spectrometer to the spacecraft in its
    pre-hadamard transformed format, inserted into a packet
    uncompressed and downlinked in telemetry.  On the
    ground, the spectra were extracted from telemetry, the
    hadamard transform was applied, and they were converted
    to CSV format.  The LCROSS Make Archive program read
    these files, applied the per-pixel calibration function
    and wrote them as PDS-formatted table (.TAB) and label
    (.LBL) files.
 
    Data
    ====
 
    The files in this dataset are PDS-formatted, ascii,
    single-column tables with detached label files.
 
    Coordinate System
    =================
 
    TBD
 
    Software
    ========
 
    The GSEOS Version used to generate these spectra is GSEOS
    5.2.407 (Feb 25, 2008), Python 2.2.3 (#37, Nov 28, 2003,
    04:20:20), Project Version 6.1.064.
 
    The LCROSS.py Python script used with GSEOS is Version
    Jun 11, 2008.
 
    The LCROSS Report Generator used on GSEOS created
    CCSDS.dat files is version 114.
 
    The version of Satellite Toolkit used to prepare geometric
    information for the labels is 8.1.3.
 
    The LCROSS Make Archive program used to assemble the
    PDS-formatted submission is dated 03/14/2010.

Confidence Level Overview
    =========================
 
    The confidence level is unspecified.
 
    Review
    ======
 
    This LCROSS data set was reviewed internally by the
    LCROSS science team before delivery to PDS.  This data
    set has passed a PDS peer review.
 
    Data Coverage and Quality
    =========================
 
    This data path from spectrometer to PDS involved no
    lossy compression and was fully error corrected.  No
    NSP2 packets were lost in downlink.  No NSP2 spectra
    were saturated.
 
    Limitations
    ===========
 
    At low signal to noise ratios, detector noise in the
    pre-hadamard data can result in negative raw counts for
    some pixels.  These values are not physical but are
    effectively a feature of the internally-performed dark
    subtraction inherent in this spectrometer's design.
 
    Data Compression
    ===============
 
    No data compression was used in the datapath from the
    detector to the formatted files ready for submission to
    the PDS.