8 
WAVELENGTH (MICRONS) 
RELATIVE SPECTRAL RESPONSES of a charge-coupled 
Silicon photosensor element. 
Figure 2. A comparison of the spectral response and sensitivity of the 
human eye and a silicon diode used in a CCD. 
LINE ARRAY DETECTOR 
ER. L OPTICS 
e cd a 
/ “= CAMERA MOTION 
/ 
  
- — 
CONTIGUOUS SCAN 
LINES ACROSS SCENE 
o = Figure 3. Schematic drawing of CCD linear array in "pushbroom scan 
mode" for imaging scenes from a spacecraft.