PDS_VERSION_ID                = PDS3                                          
/* label standards identifiers PDS Version 3.8 */                             
                                                                              
/* File Characteristics */                                                    
RECORD_TYPE                   = FIXED_LENGTH                                  
RECORD_BYTES                  = 50                                            
FILE_RECORDS                  = 8023                                          
MD5_CHECKSUM                  = "b74a5eb282181d02e7660e6a98dc08ff"            
                                                                              
/* Pointers to Data Objects */                                                
^TABLE                        = "GRD-L1B-150316-150423_160121-CSA-BGOC.TAB"   
PRODUCER_FULL_NAME            = "T. H. Prettyman"                             
PRODUCER_INSTITUTION_NAME     = "PLANETARY SCIENCE INSTITUTE"                 
                                                                              
/* Identification Data Elements */                                            
MISSION_NAME                  = "DAWN MISSION TO VESTA AND CERES"             
MISSION_ID                    = "DAWN"                                        
MISSION_PHASE_NAME            = "CERES SCIENCE APPROACH (CSA)"                
TARGET_NAME                   = "1 CERES"                                     
TARGET_TYPE                   = "ASTEROID"                                    
INSTRUMENT_HOST_NAME          = "DAWN"                                        
INSTRUMENT_HOST_ID            = "DAWN"                                        
INSTRUMENT_ID                 = "GRAND"                                       
INSTRUMENT_NAME               = "GAMMA-RAY AND NEUTRON DETECTOR"              
DATA_SET_ID                   = "DAWN-A-GRAND-3-RDR-CERES-COUNTS-V1.0"        
DATA_SET_NAME = "DAWN GRAND CALIBRATED (RDR) CERES COUNTS V1.0"               
PRODUCT_ID                    = "GRD-L1B-150316-150423_160121-CSA-BGOC"       
PRODUCT_TYPE                  = "DATA"                                        
PRODUCT_VERSION_ID            = "1.0"                                         
START_TIME                    = 2015-03-16T23:59:03                           
STOP_TIME                     = 2015-04-23T23:58:03                           
SPACECRAFT_CLOCK_START_COUNT  = "0479822515.000"                              
SPACECRAFT_CLOCK_STOP_COUNT   = "0483105655.000"                              
PRODUCT_CREATION_TIME         = 2016-01-21T16:55:52                           
SPICE_FILE_NAME               = ("naif0011.tls",                              
"dawn_203_sclkscet.00063.tsc")                                                
                                                                              
/* Data Object Definitions */                                                 
OBJECT                        = TABLE                                         
 ROWS                         = 8023                                          
 ROW_BYTES                    = 6188                                          
 COLUMNS                      = 4                                             
 INTERCHANGE_FORMAT           = ASCII                                         
 DESCRIPTION                  = "                                             
                                                                              
  This data file contains a time series of corrected and calibrated pulse     
  height spectra measured by GRaND's bismuth germanate (BGO) scintillator     
  during Ceres encounter. Each row contains the spacecraft clock (SCLK) ticks 
  and spacecraft event UTC time (SCET_UTC) corresponding to the end of the    
  science accumulation interval (accurate to 1s). The ephemeris time for the  
  midpoint of the science interval is also included. Each row also contains   
  the corresponding 1024-channel BGO spectrum accumulated. Each spectrum has  
  been subjected to the following corrections:                                
                                                                              
    - Removal of analog-to-digital (ADC) differential nonlinearity artifacts  
    - Gain and offset correction to put each spectrum on the same pulse height
                                                                              
  For each channel, the corresponding mid-point pulse height can be determined
  by multiplying channel index (0-1023) by 8.9 keV/channel.                   
                                                                              
  The processing steps, including criteria for including spectra in the time  
  series, are described by Yamashita and Prettyman, ''Dawn's Gamma Ray and    
  Neutron Detector: BGO Data Processing'', which can be found in the DOCUMENT 
  directory of this archive.                                                  
                                                                              
  Each record in this file can be matched to a record in the Ephemerides,     
  Pointing, and Geometry (EPG) data file using the 9 digit SCLK code. The EPG 
  file contains additional information needed for analysis and mapping,       
  including the measurement time, spacecraft pointing and position, the solid 
  angle of Ceres, instrument state information, and a proxy for galactic      
  cosmic ray counting rates.                                                  
  "                                                                           
                                                                              
 OBJECT                       = COLUMN                                        
  NAME                        = "SCLK"                                        
  DATA_TYPE                   = ASCII_INTEGER                                 
  UNIT                        = SECONDS                                       
  START_BYTE                  = 1                                             
  BYTES                       = 10                                            
  FORMAT                      = "I10"                                         
  DESCRIPTION                 = "                                             
    SCLK ticks at the end of the science accumulation interval (s) Each       
    science data record has a unique SCLK value, which can be used as an      
    identifier.                                                               
   "                                                                          
 END_OBJECT                   = COLUMN                                        
                                                                              
 OBJECT                       = COLUMN                                        
  NAME                        = "SCET_UTC"                                    
  DATA_TYPE                   = TIME                                          
  UNIT                        = "N/A"                                         
  START_BYTE                  = 11                                            
  BYTES                       = 20                                            
  FORMAT                      = "A20"                                         
  DESCRIPTION                 = "                                             
    UTC S/C event time (SCET) at the midpoint of the science accumulation     
    interval.                                                                 
   "                                                                          
 END_OBJECT                   = COLUMN                                        
                                                                              
 OBJECT                       = COLUMN                                        
  NAME                        = "ET_MID"                                      
  DATA_TYPE                   = ASCII_REAL                                    
  UNIT                        = "SECONDS"                                     
  START_BYTE                  = 31                                            
  BYTES                       = 12                                            
  FORMAT                      = "F12.1"                                       
  DESCRIPTION                 = "                                             
    Ephemeris time at the midpoint of the science accumulation interval (s).  
   "                                                                          
 END_OBJECT                   = COLUMN                                        
                                                                              
 OBJECT                       = COLUMN                                        
  NAME                        = "BGOC"                                        
  DATA_TYPE                   = ASCII_INTEGER                                 
  UNIT                        = "COUNTS"                                      
  START_BYTE                  = 43                                            
  BYTES                       = 6144                                          
  ITEMS                       = 1024                                          
  ITEM_BYTES                  = 6                                             
  FORMAT                      = "I6"                                          
  DESCRIPTION                 = "                                             
    1024-channel, calibrated BGO spectrum. The pulse height of each channel   
    I=0,1023 is given by 8.9 x I with units of keV.                           
   "                                                                          
 END_OBJECT                   = COLUMN                                        
                                                                              
END_OBJECT                    = TABLE                                         
                                                                              
END