NavList:

   

Reply

George-
 
 On checking for index error, I read that one should not use any targets that 
are less than three miles distant. I don't remember the source (Blewitt, 
Bowditch?) only that it was a respected source. Apparently using convenient 
telegraph poles & such can actually cause error, since there is still 
significant (parallax?) error when the objects are so close. This presents 
another problem in that the visible horizon may be only three miles away.

Wouldn't it be better to use one of the other methods such as bringing the two 
images of the sun together, innner then outer, and checking index error that 
way?

   

Reply