1 to 2 => 
  
    
  
2 to 1 =>
  
  
    
2 to 3 =>
  
  
    
3 to 2 => 
  
  
    
3 to 1 => 
  
  
1 to 3 =>
  
 
  
 
Start-bias => 
    
  
 
Start-no bias => 
    
   
    
  
Mark 1 lat =>
  
    
  
Mark 1 long =>
  
  
  
Mark 2 lat =>
  
  
    
Mark 2 long =>
  
  
    
Mark 3 lat =>
  
  
    
Mark 3 long =>