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I've used Pubs 229 and 249, as well as Norie's cosine-haversine tables for
solving the spherical triangle and ABC tables for azimuth. In general, Pub
229 is good to it's full precision of about 0.1 NM and 0.1 deg in azimuth
(roughly the same as the Nautical Almanac's accuracy in GHA and declination)
while Pub 249 is only taken to the nearest 1 NM and 1 deg in azimuth.
Norie's has five place natural/log haversine and log cosine functions tables
that can be interpolated to the nearest 0.1 min of angle and, when I have
compared them, has shown in practice answers similar to that of Pub 229. The
ABC table can also be interpolated by eye to 0.1 deg in azimuth to match 229
results.

I like Norie's compact size (Burton's is even smaller but its tables carry
less precision, giving answers more like those of Pub 249) and if room
allows, I will carry Pub 249 vol 1, 2, and 3 for plannig sights and quick
work and also carry Norie's for sight reduction or sailings problems not
covered by the declination range or stars listed in 249. Plus it's just fun
to do a sight reduction using the cosine-haversine method!

Norie's gives the observation "How far a Navigator is justified in working
to tenths of a minute is a matter that can be argued about indefinitely, but
since the nautical almanac gives hour angles and declinations to tenths of a
minute and modern sextant with a decimal vernier enables readings to be
taken to tenths of a minute as well, it would seem only logical to use
navigation tables which, with the minimum of effort, provide for the same
order of precision" (Norie's Nautical Tables, Capn. A. G.Blance (ed),
Revised Edition 1991, pp 13-14).

Rod Deyo

----- Original Message -----
From  "Cap'n MCL Rodaway" 
To: 
Sent: Friday, January 25, 2002 3:10 PM
Subject: Nories tables vs H.O. table's


> I was trained using the Norie's Navigational Tables back when I was an
> officer cadet.  I've never used the HO tables, though I have looked at
them
> a little.  Has anyone used both?  Do you find one to be more accurate then
> the other?  One thing is for certain, Nories is a lot easier to carry then
a
> stack of HO's.
>
> Yours Aye
> Michael Rodaway

   

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