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, 17:13 -0400
From: Stan K
Date: 2015 Jun 18, 17:13 -0400
Hanno,
Several of you suggestions would definitely be included if this ever became part of Celestial Tools, but the program is only known to NavList members I don't see the need for, say, an example. If it does become part of Celestial Tools, there will be an extensive Help, just like for all the other SR methods
I hesitated adding the annotation because yours was not the same as Greg's. Now that I have your approval of Greg's annotation I will probably do it.
I have no plans for adding the azimuth graph. I think just showing Z and Zn is enough of a check.
Yeah, maybe more space on the left might look better, but if I did it for hav-Doniol and then included it in Celestial Tools, I would have to do it for all the other SR methods, which I am reluctant to do.
FYI, the Power Squadrons Navigation course currently includes the following as parts of its suggested Emergency Navigation Kit:
1) a scientific calculator (possibly a celestial navigation calculator)
2) the Nautical Almanac (an outdated Almanac can be used for stars and the sun with acceptable error by emergency standards; not so old that it doesn't contain NAO Concise)
3) navigation tables (NAO Concise (we call it NASR) recommended to save space)
Items 2 (an outdated one) and 3 seem enough to reduce sun and star sights. Even Geoffrey Kolbe's Long Term Almanac only includes the sun and stars. What I am thinking of doing is suggesting that they specificially mention hav-Doniol as an alternative to NASR, as it only required two sheets of paper, your two-sided haversine table and your one-sided azimuth graph, and has the advantages of being easier and less error prone than NASR and uses the DR as the assumed position. Having a working calculator, even a four-function non-scientific one, would help with the single multiplication, but is not really necessary.
Stan
-----Original Message-----
From: Hanno Ix <NoReply_HannoIx@fer3.com>
To: slk1000 <slk1000@aol.com>
Sent: Thu, Jun 18, 2015 4:19 pm
Subject: [NavList] Re: Hav-Doniol checker
"Algebraic convention" v.s. "?????" In a recent posting I called
the missing alternative temporarily Greg's Rules but that
would not do you any good. Maybe there is such a name:
"Bowditch convention" or "Sailor's Convention" or "Navy Convention".
I might include a tab: "Example" - maybe that would help explaining.
As to the number of digits to be used: I have yet to find an example were more digits
would be desirable but if you come across one please let me know.
And as to the azimuth: I believe showing it (with invisible calculation) could be a help
for checking ones own result otherwise obtained.
From: Hanno Ix <NoReply_HannoIx@fer3.com>
To: slk1000 <slk1000@aol.com>
Sent: Thu, Jun 18, 2015 4:19 pm
Subject: [NavList] Re: Hav-Doniol checker
Stan,
the only issue I see is to find descriptive names for the choices:
Actually, "Sailor's convention" does ring good in my ears.
Indeed, a choice of
decimal vs
deg / arc min might be useful for people that
cross check with calculators.
As to the graph: I definitely would include naming the axis'; 1: Dec, 2: LHA, 3: Hc, 4: Z
or whatever your choice.
Further, it would be nice if you included the annotation: "p = ", "n = ", "q = "
Further, it would be nice if you included the annotation: "p = ", "n = ", "q = "
which is what Greg uses throughout because it sensibly describes the advancing process.
Finally a low-level idea as to the appearance of the screen: You may perhaps
want to leave some more space on the left side just for the looks.
want to leave some more space on the left side just for the looks.
Rather helpful tool!
H
On Thu, Jun 18, 2015 at 9:56 AM, Stan K
<NoReply_StanK@fer3.com> wrote:
Hanno,
About your sign convention suggestion, unless I am not thinking clearly (wouldn't be the first time), the only difference I can see in the program is that there would be no need to show "(same name)" or "(contrary name)" by the value. Am I wrong?
Stan
-----Original Message-----
From: Hanno Ix < NoReply_HannoIx@fer3.com>
To: slk1000 <slk1000---.com>
Sent: Wed, Jun 17, 2015 7:52 pm
Subject: [NavList] Re: Hav-Doniol checker
Stan,
works great!
It also demonstrates the simplicity of the calculations, very nice!
If you permit my advice re: sign convention itH would be to implement both and let the user switch from one to the other so one can see how each of them work and what the differences are.
I
On Wed, Jun 17, 2015 at 3:31 PM, Stan K <NoReply_StanK@fer3.com> wrote:
Thanks to those of you who responded to my question about whether L and d should be treated as signed or unsigned in the hav-Doniol solution when being taught to students. Unfortunately, there were not enough responses to make a statistically sound decision. FWIW, I am leaning toward treating them as signed.In the meantime, I made a hav-Doniol work checker for Windows (first beta attached) which should allow people just learning the method to easily check their math and haversine table use. It is in the style of the Celestial Tools SR Methods tool. It uses Gary's format, which Greg seemed to like. It also includes the option for four- or five-place haversine tables. It just gives the result of the multiplication, without showing any work, since it seems that we all have different multiplication preferences.For L and d with tenths of minutes, the math is done with the values unrounded, and the results rounded to whole minutes.As some email clients do not allow executable attachments, the program has an exx suffix. Change it to exe before running.
[from FER: changed to a .zip archive... just download and open]Let me know what you think.Stan
Attached File:
(hav-Doniol-check.zip: Open and save)
