The three custom built input stations are designed for use with 
a variety of material. Analysts often compare hardcopy of different 
size and scale. Skewed orientation and obliquity add to the difficulty 
of comparison. Although hardcopy can be rotated and some hand 
magnification is possible on scopes, overlays or side by side views 
at a 1 to 1 ratio is preferred. The main use for the SAS is visual 
change detection, the presence of new features rapidly detected, 
identified and recorded. 
The three input stations were designed by a subcontractor; each 
includes: a system cabinet containing a microprocessor, station 
controller electronics and servo systems and a camera control unit 
which includes the video camera electronics. Each microprocessor 
controller is connected to the CPU providing remote software 
communications control. Each camera is connected to the image 
processing system through the video switch. 
The cameras are controlled robotics style with the custom designed 
system software or locally with the station controller. They have 
four degrees of freedom: horizontal movement along the x and y axes 
over any position on a 48" X 64" area, vertical movement for a 1 inch 
to 10 inch field of view and camera rotation of 100 degrees in % degree 
increments. All three video cameras are black and white, but the 
two map/chart stations have RGB color filters. This allows us to 
digitize an analog video signal into a 1024 X 1024 digital frame using 
256 shades of "pseudo color". (Data: is stored as 8 bit values: 3 
bits red, 3 blue and 2 green.) A black and white digital image can 
also be made from the video input of any of the cameras. This gives 
us a 1024 X 1024 digital frame of 256 gray scale shades. Other digital 
manipulations can be added in the future. 
217