NavList:

John,

This method uses and follows the same rules as the standard sin cos formula used with pocket trig calculators. It is the ideal pocket calculator backup table and does azimuth calculations more efficiently to the tenth of a degree. Azimuth, prime vertical, and amplitude can be quickly calculated with only addition and subtraction. The working table and wallet table compares in size to the haversine table. Since the Ageton Classic and the Haversine Doniol both work off the DR assumed position they can serve as a double check against each other. If Hc is the same with each reduction then chances are that the reduction tabulations were done correctly. NA lookups could still be in error though. I also like the fact that the Ageton Classic can be done in a single vertical column. Haversine Doniol is still the champion sight reduction for Hc reductions because there are no rules through 180° of meridian angle. I remain a fan of both these new SR methods.

Greg Rudzinski

From: John D. Howard
Date: 2015 Oct 25, 10:09 -0700

Greg,

What is the advantage of the Ageton method over the Ix Haversign Doniol Method that you and Hanno worked on?

I have tried many methods and belive the Ix-Doniol is the best.  Easy, compact and as accurate as the size of the haversine tables one uses.  I know that different people prefer different methods and no one way will be everyones favorite but are there dissadvantages in the Haversign method that I am not seeing?

Thanks,    John H.