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## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

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Re: Nautical Almanac Method Reduction
From: Chuck Taylor
Date: 2000 Nov 05, 9:29 PM

```Gord,

I'm assuming you know how to figure Assumed Lat and Assumed LHA.  Given
that,

1.  A  = arcsine( cos(Lat) * sin(LHA) )
2.  Z1 = arcsine( cos(LHA) / cos(A) )
3.  B  = arcsine( cos(Lat) * sin(Z1) )
4.  F  = B + Dec
5.  F = round(F); F' = fractional part of F
6.  A = round(A); A' = fractional part of A
7.  H = arcsine( cos(A) * sin(F) )
8.  Z2 = arcsine( cos(F) / cos(H) )
9.  P =  arcsine( cos(A) * sin(Z2) )
10. Corr1 = F' sin(P)
11. Corr2 = A' cos(Z2)

Is this what you are looking for?

Regards,

Chuck Taylor
Everett, WA, USA

gord wrote:

...
> What I'm looking for is to generate the values in the NOA sight reduction
> tables;  A,B,Z1,H,PZ2, and the values from the aux. tables.
>
...
>
> Thanks
> Gord
```
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