Terrain with siope S 
7 
bons] beu 
Section through Terrain 
in vertical plane orierrted 
in the direction of 
Sfeepes]! slope. 
Figure 4: 
  
     
   
Magritude 
of Slope S 
Aunt 
P di 
Relating  Ploffizó Error AD to 
Equivalent height error AZ 
Direction of steepest 
Slope of ferrain 
Tracking point