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I just returned from a couple of weeks in Alaska (off the grid) and have been 
catching up on my emails. Reading this topic i have to ask the question, 
"why?
The sextants we have are "accurate enough" for their purpose, getting us 
withing the range of more accurate systems of navigation at the point where 
such greater accuracy becomes necessary. Nobody seems to want to admit this, 
and it is different from the needs of surveying. There are clearly stated 
requirements for GPS positioning since it is to be used for harbor and 
channel navigation and for aircraft instrument approaches. In the aviation 
sector there are precisely stated requirements for the different segments of 
flight, enroute versus approach, which considers the precision and accuracy 
of the type of navigation signal being utilized (GPS, NDB, VOR, Localizer, 
DME) along with the distance from the transmitter. This is all spelled out in 
TERPS, FAA_Order_8260.3C.pdf available on the FAA.GOV website. 

Celestial navigation is an "enroute" navigation system and its accuracy, both 
on sea and in the air, are good enough for that purpose. There is no reason 
to try to "make a silk purse out of a sow's ear" when a sow's ear is all you 
need. 

gl

   

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