PDS_VERSION_ID      = PDS3                                                    
LABEL_REVISION_NOTE = "                                                       
  2006-08-02  A.C.Raugh  Updated to current standards                         
  "                                                                           
                                                                              
OBJECT     = DATA_SET                                                         
  DATA_SET_ID = "GIO-C-OPE-3-RDR-GRIGG-SKJELL-V1.0"                           
                                                                              
  OBJECT     = DATA_SET_INFORMATION                                           
    DATA_SET_NAME                  = "GIOTTO EXTENDED MISSION, OPE, V1.0"     
    DATA_SET_COLLECTION_MEMBER_FLG = "Y"                                      
    DATA_OBJECT_TYPE               = "TABLE"                                  
    START_TIME                     = 1992-07-10T14:16:39.071                  
    STOP_TIME                      = 1992-07-10T16:14:59.287                  
    DATA_SET_RELEASE_DATE          = 1995-12-31                               
    PRODUCER_FULL_NAME             = "PDS SMALL BODIES NODE"                  
    DETAILED_CATALOG_FLAG          = "N"                                      
    ARCHIVE_STATUS                 = "SAVED"                                  
    DATA_SET_TERSE_DESC            = "                                        
      Raw abd calibratred Optical Probe Experiment results from the           
      Giotto extended mission to comet 26P/Grigg-Skjellerup (SAVED            
      DATA)"                                                                  
    ABSTRACT_DESC                  = "                                        
      This dataset includes raw and calibrated results from the Optical       
      Probe Experiment (OPE) aboard the Giotto spacecraft during its extended 
      mission to comet 26P/Grigg-Skjellerup, as well as the data used in the  
      calibration.                                                            
      "                                                                       
    CITATION_DESC                  = "N/A"                                    
                                                                              
    DATA_SET_DESC                  = "                                        
      Data Set Overview                                                       
      =================                                                       
      This dataset includes raw and calibrated results from the Optical       
      Probe Experiment (OPE) aboard the Giotto spacecraft during its extended 
      mission to comet 26P/Grigg-Skjellerup, as well as the data used in the  
      calibration.                                                            
                                                                              
           Description of the instrument by A. C. Levasseur-Regourd:          
                                                                              
           'The OPE polarimeter was designed to measure the polarized         
        components of the light in seven bandpasses or channels, ranging      
        from the near ultraviolet to the near infrared. Three channels (so-   
        called blue, green and red) were devoted to the observation of the    
        scattering of solar light by cometary dust grains, in emission-free   
        countinuum bands. Four other channels (so called OH, CN, CO+, C2)     
        were devoted to the observation of light emitted by cometary          
        gases.                                                                
                                                                              
           'The imaging of a mosaic of interference filters (placed in front  
        of the objective lens and organized into a mosaic to compensate for   
        the chromatic effects) onto a microchannel plate allowed the          
        spectral discrimination to be achieved. A polaroid analyzer, placed   
        in front of each filter, except the CO+ one, allowed the polarization 
        to be determined by the rotation of the analyzer with the spin of     
        the spacecraft. During a spin period (of approximately 4 seconds),    
        eight consecutive measurements of the polarized intensity, Ii, Ii+1,  
        Ii+2, etc, (of approximately half a second each), were performed in   
        the seven channels at eight so-called clock angles.'                  
                                                                              
      Parameters                                                              
      ==========                                                              
      The principal parameter in each dataset is counts in each channel.      
      The raw data file contains a time-ordered list of counts in all         
      instrument channels.  Two separate files provide calibrated results     
      in two of the bands (blue and green continuum), listed with respect to  
      distance along the track of the spacecraft.  This distance has its zero 
      point at the nominal time of closest approach near 15:30:45.            
                                                                              
      Data                                                                    
      ====                                                                    
      There are four separate data files:                                     
                                                                              
          operaw    Raw, decommuted counts in chronological order             
          opeblue   Calibrated counts as a function of distance,              
                    blue continuum                                            
          opegreen  Calibrated counts as a function of distance,              
                    green continuum                                           
          opecal    Calibration data for both blue and green filters          
      "                                                                       
    CONFIDENCE_LEVEL_NOTE          = "                                        
      Confidence Level Overview                                               
      =========================                                               
      See the accopmanying documentation (opechan.doc) file for a discussion  
      of the sensitivity and residual effects on the OPE instrument from the  
      preceding encounter with comet 1P/Halley.                               
                                                                              
      Review                                                                  
      ======                                                                  
      This data set never underwent formal PDS review.                        
      "                                                                       
                                                                              
  END_OBJECT = DATA_SET_INFORMATION                                           
                                                                              
  OBJECT     = DATA_SET_MISSION                                               
    MISSION_NAME = "GIOTTO EXTENDED MISSION"                                  
  END_OBJECT = DATA_SET_MISSION                                               
                                                                              
  OBJECT     = DATA_SET_TARGET                                                
    TARGET_NAME = "26P/GRIGG-SKJELLERUP 1 (1922 K1)"                          
  END_OBJECT = DATA_SET_TARGET                                                
                                                                              
  OBJECT     = DATA_SET_HOST                                                  
    INSTRUMENT_HOST_ID = "GIO"                                                
    INSTRUMENT_ID      = "OPE"                                                
  END_OBJECT = DATA_SET_HOST                                                  
                                                                              
  OBJECT     = DATA_SET_REFERENCE_INFORMATION                                 
    REFERENCE_KEY_ID = "LEVASSEUR-RETAL1993"                                  
  END_OBJECT = DATA_SET_REFERENCE_INFORMATION                                 
                                                                              
END_OBJECT = DATA_SET                                                         
                                                                              
END