PDS_VERSION_ID        = PDS3                                                  
LABEL_REVISION_NOTE   = "                                                     
  2004-08-25  S.McLaughlin  Created                                           
  2005-02-07  S.McLaughlin  Resolved liens                                    
"                                                                             
                                                                              
OBJECT                = INSTRUMENT                                            
  INSTRUMENT_HOST_ID  = "DII"                                                 
  INSTRUMENT_ID       = "ITS"                                                 
                                                                              
  OBJECT              = INSTRUMENT_INFORMATION                                
    INSTRUMENT_NAME   = "DEEP IMPACT IMPACTOR TARGETING SENSOR - VISIBLE CCD" 
    INSTRUMENT_TYPE   = "CCD CAMERA"                                          
    INSTRUMENT_DESC   = "                                                     
                                                                              
                                                                              
    The instrument overview was provided by Dr. Michael A'Hearn, the          
    principal investigator for the Deep Impact mission.  For a detailed       
    discussion of the instrument, see Hampton, et al. (2005)                  
    [HAMPTONETAL2005].                                                        
                                                                              
                                                                              
    Instrument Overview                                                       
    ===================                                                       
                                                                              
    The Impactor Targeting Sensor (ITS) consists of an f/17.5 Cassegrain      
    telescope feeding directly onto a CCD for direct, optical imaging.        
    It is an exact clone of the Medium Resolution Instrument and its          
    visual CCD camera except that the filter wheel has been deleted.          
    In all other respects it is identical.                                    
                                                                              
    The ITS telescope is a classical Cassegrain design with the following     
    parameters:                                                               
                                                                              
      Primary aperture        : 12.0 cm diameter, round                       
      Primary focal ratio     :  3.75                                         
      Secondary Obscuration   :  6.6 cm diameter, round                       
      Secondary magnification :  4.75x (net Cassegrain focal length 210 cm)   
      Back focal distance     : 30.0 cm                                       
                                                                              
    The visual detector is a 1024 x 1024 split frame-transfer CCD with        
    21-micron-square pixels.  The electronics allow readout of centered       
    sub-frames in multiples of 2, 64x64, 128x128, and so on, with or          
    without rows of overscan.  Transfer time, to move the two halves          
    of the image from the exposing area to the two shielded areas is          
    about 5.2 msec.  There are readout amplifiers in each of the four         
    quadrants.  Readout time for a full frame is 1.8 seconds.  Net            
    pixel scale is 10 microradians/pixel (2 arcseconds/pixel).  The           
    surface scale is 0.2 meters/pixels at 20 kilometers.  Images are          
    transmitted to the flyby spacecraft for re-transmission to Earth.         
                                                                              
    The ITS instrument is mounted behind the main deck of the impactor        
    spacecraft and looks through a rectangular cutout on one edge of the      
    copper cratering mass at the front of the impactor.                       
                                                                              
"                                                                             
                                                                              
  END_OBJECT          = INSTRUMENT_INFORMATION                                
                                                                              
  OBJECT              = INSTRUMENT_REFERENCE_INFO                             
    REFERENCE_KEY_ID  = "HAMPTONETAL2005"                                     
  END_OBJECT          = INSTRUMENT_REFERENCE_INFO                             
                                                                              
END_OBJECT            = INSTRUMENT                                            
END