117 



^3 ^ 1^°° ^ ^1 (6.3c) 



?2' = 33+ 270' + .2 (6.3d) 



The sum of Equations 6.3 a through d is; 



4 4 



y B ' = 4B, + y e (6. A) 



^, n 3 , n 



n=l n=l 



From Equation 6.2, 



^3=1 ^, ^n' (6.5) 



n=l 



and the corresponding orientation for each of the other three arms 

 may be found by subtracting Equations 6.3 from 6.1. The corrected 

 orientation headings for each arm and for each type of compass used 

 are listed in Table 6.1. Somewhat surprisingly, the agreement 

 between the corrected averages of the arm headings as found using the 

 expensive digital compass and the simple wrist compasses is very good 

 — within 0.14 degrees of one another. The final orientation of each 



