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Re: Fw: Chichester's Calculations ( Sine-Cosine method)
From: Dave Walden
Date: 2008 Dec 15, 05:36 -0800

```Here's an HO 211 solution:

Hearty thanks to (and check out his other great programs!):

REM HO-211 SIGHT REDUCTION v3.9
REM 22 OCTOBER 2004

Give K the same name as Dec.

K~L: Add K and Lat, if contrary name.
Subtract smaller from larger, if same name.

If t > 90� then take K from bottom of table (90�-180�).

Take Z from bottom of table (90�-180�) except when K is same name as Lat
and greater than Lat, then take Z from top of table (0�-90�).

If Lat = N and t = E then Zn = Z
If Lat = N and t = W then Zn = 360�-Z
If Lat = S and t = E then Zn = 180�-Z
If Lat = S and t = W then Zn = 180�+Z
Lat > 0� is N,  t > 0� is W
Lat < 0� is S,  t < 0� is E

K and T angles within 8� of 90� cause inaccurate Hc, interpolate B(R)

If A(Z) is negative when Z is near 90�, then interpolate B(Hc), or use zero

Hc is below horizon if K~Lat > 90�

PRESS ENTER TO CONTINUE ?

LAT=   43�00.0'N,  DEC=   20�06.0'N
LHA=  339�00.0'W,  T  =   21�00.0'E

A(Dec)= 46387.0
-B(R)  =  2610.0  Interpolation OFF
-----------
A(K)  = 43777.0      ?    K  =  21�24.5'N
+-Lat=  43�00.0'N
-------------
B(K~L)=  3160.0      ?    K~L=  21�35.5'
+B(R)  =  2610.0
-----------
A(Hc) =  5770.0      ?    Hc =+ 61�07.0'

A(t)  =     1.1
+B(Dec)=  2729.0
-----------
A(R)  = 47296.0
-B(Hc) = 31603.0  Interpolation OFF
-----------
A(Z)  = 15693.0      ?    Z = N 135.8� E,  Zn = 135.8� T

Verify: Hc =  61�06.7',  Z = 135.8�,  Zn = 135.8�

PRESS 'Y' TO CONTINUE

E

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