 observer. The one-way light time, 'lt', is given by 
 
                | T(et) - O(et) | 
         lt = ------------------- 
                        c 
 
      The geometric relationship between the observer, target, and 
      solar system barycenter is as shown: 
 
 
         SSB ---&gt; O(et) 
          |      / 
          |     / 
          |    /                            
          |   /  T(et) - O(et)   
          V  V                                   
         T(et) 
 
 
      The returned positi