4 
described in platform coordinates.) The next step in the process, referred to in Figure 2 as 
"Advanced Processing" converts the calibrated DN's into physically related quantities such as 
reflectance, emittance etc. and places these in a geographic coordinate system (i.e. they are 
geocoded). By placing calibrated physical measurements in a geographic coordinate system we 
achieve two objectives: 1)The use of a common coordinate system which is independent of the 
particular geometry of the acquiring spacecraft allows measurements from various sources to be 
combined and compared, and 2) the use of a common geographic coordinate system permits 
easy integration of the measurements with other map-referenced data which is already in the 
same coordinate system. 
Climate Forestry •••••••• 
Operational Users 
Oceans 
etc. 
J 
Figure 2 Information Delivery System