PDS_VERSION_ID                    = PDS3                                       
LABEL_REVISION_NOTE               = "2019-04-05, V. DELLA CORTE"               
RECORD_TYPE                       = STREAM                                     
                                                                               
OBJECT                            = DATA_SET_MAP_PROJECTION                    
 DATA_SET_ID                         = "RO-C-GIA-5-67P-DUST-MAPS-V1.0"         
 OBJECT                           = DATA_SET_MAP_PROJECTION_INFO               
  MAP_PROJECTION_TYPE             = "SIMPLE CYLINDRICAL"                       
  MAP_PROJECTION_DESC             = "                                          
                                                                               
    In the simple cylindrical projection [SNYDER1987], parallels               
    of latitude and meridians of longitude are straight lines that             
    are perpendicular to one another.                                          
                                                                               
    This map projection is obtained from the Latitudinal coordinates           
    obtained transforming rectangular coordinates of the 67P/C-G CSO           
    reference frame. The CSO reference frame is defined as follows:            
                                                                               
      -  The position of the sun relative to the body is the primary           
         vector: the X axis points from the body to the sun.                   
                                                                               
      -  The inertially referenced velocity of the sun relative to the         
         body is the secondary vector: the Y axis is the component of          
         this velocity vector orthogonal to the X axis.                        
                                                                               
      -  The Z axis is X cross Y, completing the right-handed reference        
         frame.                                                                
                                                                               
      -  All vectors are geometric: no aberration corrections are used.        
    For the transformation to Latitude and Longitude the X axis is             
    considered as the prime meridian.                                          
    The map is evaluated at a reference distance of 15 km.                     
                                                                               
    The transformation from latitude and longitude (LAT, LON) in               
    degrees to LINE and SAMPLE is given by the following equations.            
    Longitude increases from west to east.                                     
    The transformation from latitude and longitude (LAT, LON) in               
    degrees to LINE and SAMPLE indices is given here by the following          
    equations.                                                                 
    Longitude increases from west to east and is non-negative.                 
                                                                               
      SAMPLE = INT(SAMPLE_PROJECTION_OFFSET +                                  
          RES * (LON - CENTER_LONGITUDE)) + 1                                  
                                                                               
      LINE = INT(LINE_PROJECTION_OFFSET - RES * (LAT - CENTER_LATITUDE)) + 1   
                                                                               
    where:                                                                     
                                                                               
    LAT and LON                                                                
      are the latitude and longitude of a given spot on the spherical          
      surface where measures are rescaled  and reported in the AXIS keyword    
      Of the Label for each map                                                
                                                                               
    LINE_PROJECTION_OFFSET                                                     
      is the line number on which the map projection origin                    
      occurs; i.e., the line number that corresponds to the center             
      latitude.                                                                
                                                                               
    SAMPLE_PROJECTION_OFFSET                                                   
      is the sample number on which the map projection origin                  
      occurs; i.e., the sample number that corresponds to the center           
      longitude.                                                               
                                                                               
    CENTER_LONGITUDE, CENTER_LATITUDE                                          
      are the longitude and latitude chosen as the origin of the               
      map projection.                                                          
                                                                               
    RES (MAP_RESOLUTION)                                                       
      is the number of pixels per degree at the projection origin.             
                                                                               
    Values for LINE_PROJECTION_OFFSET, SAMPLE_PROJECTION_OFFSET,               
    CENTER_LONGITUDE, CENTER_LATITUDE, and MAP_RESOLUTION are found            
    in the IMAGE_MAP_PROJECTION object in an image's PDS label.                
                                                                               
    In the above definitions, a pixel is assumed to cover an area, and         
    the integral values of LINE and SAMPLE are assumed to correspond to        
    the center of the area. The pixel in the upper left corner is line 1,      
    sample 1. The latitude and longitude corresponding to the center of        
    pixel (1,1) are maximum latitude - 1/(RES*2) and westernmost longitude     
    + 1/(RES*2). The top edge of pixel (1,1) has the maximum latitude in       
    the image. The left edge of pixel (1,1) has westernmost longitude          
    in the image."                                                             
                                                                               
  ROTATIONAL_ELEMENT_DESC         = "See [PREUSKERETAL2015]."                  
                                                                               
  OBJECT                          = DS_MAP_PROJECTION_REF_INFO                 
   REFERENCE_KEY_ID               = "PREUSKERETAL2015"                         
  END_OBJECT                      = DS_MAP_PROJECTION_REF_INFO                 
                                                                               
  OBJECT                          = DS_MAP_PROJECTION_REF_INFO                 
   REFERENCE_KEY_ID               = "SNYDER1987"                               
  END_OBJECT                      = DS_MAP_PROJECTION_REF_INFO                 
                                                                               
  OBJECT                          = DS_MAP_PROJECTION_REF_INFO                 
   REFERENCE_KEY_ID               = "SEIDELMANNETAL2002"                       
  END_OBJECT                      = DS_MAP_PROJECTION_REF_INFO                 
                                                                               
 END_OBJECT                       = DATA_SET_MAP_PROJECTION_INFO               
END_OBJECT                        = DATA_SET_MAP_PROJECTION                    
                                                                               
END