PDS_VERSION_ID        = PDS3                                                  
LABEL_REVISION_NOTE   = "                                                     
  2004-08-25  S.McLaughlin  Created                                           
  2005-02-07  S.McLaughlin  Resolved liens from Oct 2004 thermal-vac review   
  2005-05-22  DI:McLaughlin Resolved liens from Oct 2006 peer review          
"                                                                             
                                                                              
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   = "                                                     
                                                                              
                                                                              
  Instrument Overview                                                         
  ===================                                                         
    The Impactor Targeting Sensor (ITS) consisted of an f/17.5 Cassegrain     
    telescope feeding directly onto a CCD for direct, optical imaging. It     
    was an exact clone of the Medium Resolution Instrument and its visual     
    CCD camera except that the filter wheel had been deleted. In all other    
    respects it was identical.                                                
                                                                              
    The ITS telescope was 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 detector was a 1024 x 1024 split frame-transfer CCD with              
    21-micron-square pixels.  The electronics allowed 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 was about      
    5.2 milliseconds.  There were readout amplifiers in each of the four      
    quadrants.  Readout time for a full frame was 1.8 seconds.  Net pixel     
    scale was 10 microradians/pixel (2 arcseconds/pixel).  The surface        
    scale was 0.2 meters/pixels at 20 kilometers.  Images were transmitted    
    to the flyby spacecraft for re-transmission to Earth.                     
                                                                              
    The ITS instrument was mounted behind the main deck of the impactor       
    spacecraft and looked through a rectangular cutout on one edge of the     
    copper cratering mass at the front of the impactor.                       
                                                                              
    For a detailed discussion of the instrument, see Hampton, et al.          
    (2005) [HAMPTONETAL2005].  This instrument overview was provided by       
    Dr. Michael A'Hearn, the principal investigator for the Deep Impact       
    mission.                                                                  
                                                                              
                                                                              
  Instrument Calibration                                                      
  ======================                                                      
    The ITS instrument was calibrated by using in-flight data as well as      
    pre-launch data taken during a thermal-vacuum test (TV3) performed        
    in January and February 2003.  The calibration of the ITS instrument      
    was discussed in the 'Deep Impact Instrument Calibration' paper by        
    Klaasen, et al. (2006) [KLAASENETAL2006].                                 
                                                                              
                                                                              
  Flight Performance                                                          
  ==================                                                          
    The ITS instrument generally performed as expected during flight.         
                                                                              
"                                                                             
                                                                              
  END_OBJECT          = INSTRUMENT_INFORMATION                                
                                                                              
  OBJECT              = INSTRUMENT_REFERENCE_INFO                             
    REFERENCE_KEY_ID  = "HAMPTONETAL2005"                                     
  END_OBJECT          = INSTRUMENT_REFERENCE_INFO                             
                                                                              
  OBJECT              = INSTRUMENT_REFERENCE_INFO                             
    REFERENCE_KEY_ID  = "KLAASENETAL2006"                                     
  END_OBJECT          = INSTRUMENT_REFERENCE_INFO                             
                                                                              
END_OBJECT            = INSTRUMENT                                            
END