NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Abhav vs S-Tables
From: Stan K
Date: 2016 Sep 21, 10:50 -0400
From: Stan K
Date: 2016 Sep 21, 10:50 -0400
With all this recent interest in the Abhav sight reduction method, I decided to put together an Abhav "checker", the first beta of which is attached. I have not added this checker to Celestial Tools, as I feel it does not meet my definition of "mainstream", as having been published in a non-electronic book.
Checkers for the other sight reduction methods mentioned in Robert's message are included in Celestial Tools, the latest version of which is also attached. Included in the SR Methods tool are Ageton, Ageton-Bayless (including the Sadler method), and the S-Table (Pepperday and Farley versions), along with checkers for several other methods popular (and some not so popular) among NavList members.
To be clear, these checkers are intended to be used as a learning aid, to check work done manually. This new Abhav checker has had minimal testing (especially little for table values that include tenths), so please report any bugs you might find in this checker and in Celestial Tools.
Stan
-----Original Message-----
From: Robert VanderPol II <NoReply_RobertVanderPolII@fer3.com>
To: slk1000 <slk1000@aol.com>
Sent: Tue, Sep 20, 2016 7:45 pm
Subject: [NavList] Re: Abhav vs S-Tables
From: Robert VanderPol II <NoReply_RobertVanderPolII@fer3.com>
To: slk1000 <slk1000@aol.com>
Sent: Tue, Sep 20, 2016 7:45 pm
Subject: [NavList] Re: Abhav vs S-Tables
I had no problem getting a new S-tables for the cover price.
The S-tables are a shortened version of Ageton with an added work sheet for working sights backwards to identify a star already shot that you were uncertain of.
Bayless is also a shortened version of Ageton. The second edition has an added worksheet with an alternate method (Sadler) for when one of the intermediate values is close to 90o and the final result can be in error upto 30'.
Within the last 3 months there was a long running thread started by PaulH who used a random selection of 1,000,000 sights reduced by the above Ageton, Bayless, Pepperday and Sadler methods and compared results to direct mathematical reduction and provided the statistics showing how they all and when it might be advantageous to use one rather than the other.
File: 136610.abhavbeta1.zip
