Data Set Overview :  This data set contains raw 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 approximately 80 degrees in radius.  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_RAW_.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 raw 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_CAL 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 NSP1_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 and wrote them as a 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.