Data Set Overview
    =================
      The Dynamic Albedo of Neutrons (DAN) is an active/passive
      neutron spectrometer that measures the abundance and depth
      distribution of H- and OH-bearing materials (e.g., adsorbed
      water, hydrated minerals) in a shallow layer (~1 m) of Mars'
      subsurface along the path of the MSL rover.  In active mode,
      DAN measures the time decay curve (the dynamic albedo) of
      the neutron flux from the subsurface induced by its pulsing
      14 MeV neutron source (Figure 1 shows an example).  A detailed
      description of the DAN instrument and scientific investigation
      can be found in Litvak et al. (2008).
 
      The MSL DYNAMIC ALBEDO OF NEUTRON DETECTOR consists of 5 RDR data
      types. Three are a time series collection of science and housekeeping
      data from the MSL rover.
      Data are sorted by time, with each data file containing one
      sol's worth of data. Measurements are assigned to a particular
      sol based on the start of the collection interval.
 
 
    Parameters
    ==========
       The DAN RDR data set is composed of five data types. The
       objective of compiling the DAN RDR is to create a record of
       the reduced data dervied from the EDR data collected by DAN.
       The following paragraphs discuss the parameters of interest
       in each of the data types.
 
       Derived Engineering
       -------
         The DAN engineering data set is produced from the housekeeping
         data that is in all EDR data types. The raw values are converted
         to engineering units of volts, amp, or celsius.
 
       Derived Passive
       ------------
          The PASSIVE data set is produced with high voltage applied to
          the detectors but the PNG is not pulsing. The sum of the counts
          in the CTN and CETN spectra which are background corrected and
          adjusted for detector efficiency.
 
       Derived Active
       ------------
          The ACTIVE data is is produced with high voltage applied to
          the detectors and the PNG is pulsing. The sum of the counts
          in the CTN and CETN spectra which are background corrected and
          adjusted for detector efficiency.
 
       Averaged Passive
       ------------
          The PASSIVE data set is produced with high voltage applied to
          the detectors but the PNG is not pulsing. The average of the
          Derived Passive data set over some period time. The time over
          which the data is averaged is included in the data set.
 
       Averaged Active
       ------------
          The ACTIVE data is is produced with high voltage applied to
          the detectors and the PNG is pulsing. The average of the
          Derived Active data set over some period time. The time over
          which the data is averaged is included in the data set.
 
    Processing
    ==========
      DAN's Reduced Data Records (RDR), NASA Level 1 and above products
      are generated by the DAN team from the EDR data products, which are
      produced by the Multi-Mission Data Processing and Control System (MPCS)
      on MSL.  MPCS is a component of Real Time Operations (RTO), which
      itself is part of the MSL Ground Data System (GDS).
 
 
    Data
    ====
      The DAN RDR data product contains five types of data.
 
      DAN_DERIVED_ENG      DAN housekeeping data in engineering units
      DAN_DERIVED_PASSIV   DAN reduced passive neutron data
      DAN_DERIVED_ACTIVE   DAN reduced active neutron data
      DAN_AVERAGED_PASSIV  DAN averaged reduced passive neutron data
      DAN_AVERAGED_ACTIVE  DAN averaged reduced active neutron data
 
      The first three types are time series of DAN housekeeping and science
      data. The last two are averaged over some time period.
 
 
    Coordinate System
    =================
      This data set will use the standard Mars latitude and an easting
      longitude to specify location. This spatial information will be
      calculated using the SPICE tool set along with MSL specific SPICE
      kernels.
 
    Software
    ========
      No DAN specific software is provided with this data set.
 
      PDS-labeled images and tables can be viewed with the program
      NASAView, developed by the PDS and available for a variety of
      computer platforms from the PDS web site
      http://pds.nasa.gov/tools/software_download.cfm. There is no
      charge for NASAView.

Confidence Level Overview
    =========================
      The data presented in the DAN RDR is intended to be
      processed, and reduced data set released for DAN. Data
      presented here are an accurate reduction of DAN data using
      the a derived processing technique.
 
 
    Review
    ======
      The DAN RDR was reviewed internally by the DAN team prior to
      release to the PDS. PDS will also performed an external peer
      review of the DAN RDR.
 
 
    Data Coverage and Quality
    =========================
      Data reported are the processed data received from OPGS
      in the form of EDR. All data received is processed into
      one of the RDR data types. Data are of good quality as
      the processing is based on the best available knowledge
      of the reduction algorithms used.
 
 
  Limitations
  ===========
    The major limitation of this data set is that gained knowledge
    as data is received from Mars may require the reprocessing of data
    alreay delivered the PDS due to modifications in the algorithms used
    in the data production.
 
  Data Compression
  ===============
    No data compression is used.