NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Hav-Doniol checker
From: Stan K
Date: 2015 Jun 18, 12:05 -0400
From: Stan K
Date: 2015 Jun 18, 12:05 -0400
Andres,
Thanks for sending this. It shows me other opinions about certain things that Greg and I have discussed privately. I also think I like your format because it leaves room for the letter names of the values.
You chose to take the haversine of LHA with the minutes unrounded. I went with the minutes rounded (also for the sums and difference of latitude and declination) simply because Hanno's 4-place and Robert Bernecky's 5-place haversine tables both have whole minutes as entering arguments. With Robert's you might just go with the whole minute, but with Hanno's you often have to eyeball interpolate for odd minutes, easily done if only whole minutes are considered. It makes sense to me now to use the tenths in the calculation, since eyeball interpolation would probably be done even for Robert's table anyway. Or maybe not. It is really a matter of what people would do in "real life". Maybe the thing to do is round the minutes for the 4-place table, but do not round for the 5-place table.
As far as the bottom line goes, these are all nits, as the Hc results are the same regardless.
I really didn't know what to do about azimuth. There seemed no point to showing the hav-Doniol method, since people would be using the graph. But I guess showing the azimuth angle and azimuth, even with an invisible calculation, is the way to go, since the results of using the azimuth graph need to be checked anyway.
If I do another version, I will probably leave the format as is, but use unrounded minutes for the haversine calculations if the 5-place table is used, and add Z and Zn (with no calculation or graph).
Any opinions (from anyone)?
(BTW, I noticed that at the bottom of the "index card" you show n as .0304 and m as .3012, so n + m should equal .3316, but above it appears as 0.3315.)
Stan
-----Original Message-----
From: Andrés Ruiz <NoReply_AndresRuiz@fer3.com>
To: slk1000 <slk1000@aol.com>
Sent: Thu, Jun 18, 2015 7:09 am
Subject: [NavList] Re: Hav-Doniol checker
From: Andrés Ruiz <NoReply_AndresRuiz@fer3.com>
To: slk1000 <slk1000@aol.com>
Sent: Thu, Jun 18, 2015 7:09 am
Subject: [NavList] Re: Hav-Doniol checker
An example of my test: