ABC Tables Azimuth Value

[albyreto]

Hello!!!

During my home exercises to keep me trained I have encountered some problems in which the result of the value of azimuth is different if calculated with the Eulero's formula or if calculated with the tables ABC

How is it possible?
Can you help me!

One of these act like this:
Dec -14° 39.5'
hc 21° 14.6'
Lat 40N
LHA 315° 5,1'

With the formula:
Z=88°

With ABC tables 
Z=133°

[c_davidson]

Albyreto,

No, I can't help you. It could be that when doing the calculations a negative value must be entered for LHA or use T instead of LHA. I'm no expert in the matter that's for sure.

I'm sure that doesn't help but it's an idea.

Peace,

Clen

[pabrides]

Hello!!!

During my home exercises to keep me trained I have encountered some problems in which the result of the value of azimuth is different if calculated with the Eulero's formula or if calculated with the tables ABC

How is it possible?
Can you help me!

One of these act like this:
Dec -14° 39.5'
hc 21° 14.6'
Lat 40N
LHA 315° 5,1'

With the formula:
Z=88°

With ABC tables 
Z=133°

This is what I get:

Using 249:  Z = 133

Using formula:

Z = ACOS ((SIN -14.658 - (SIN 40 X SIN 20.35)) / (COS 40 X COS 20.35)) = 131.57  (close enough)

Using your original HC I get Z = 132.89

It seems my HC is slightly different than yours.  In the 249 vol 3, using  LHA = 315, DEC = 15, APLAT = 40 contrary,    I found HC = 20:54,  d = -49,  Z = 133.
Using table 5 I found 'd' correction to be -33... So 20:54 - 00:33 = 20:21 which is eq to 20.35

good luck shipmate
joe

[EdCa]

Maties,

This might be of some help;

https://thenauticalalmanac.com/Formulas....etermine_Z

Ed

[pabrides]

Maties,

This might be of some help;

https://thenauticalalmanac.com/Formulas....etermine_Z

Ed

Hi Ed... you are always ready to launch the rescue skiff... :)  This time you swept the seas clean of any misinterpretation.  However, I went to Bowditch this time - straight from the mouth of king Neptune...  have a great weekend, shipmate.

joe

[albyreto]

Hello!!!

During my home exercises to keep me trained I have encountered some problems in which the result of the value of azimuth is different if calculated with the Eulero's formula or if calculated with the tables ABC

How is it possible?
Can you help me!

One of these act like this:
Dec -14° 39.5'
hc 21° 14.6'
Lat 40N
LHA 315° 5,1'

With the formula:
Z=88°

With ABC tables 
Z=133°

This is what I get:

Using 249:  Z = 133

Using formula:

Z = ACOS ((SIN -14.658 - (SIN 40 X SIN 20.35)) / (COS 40 X COS 20.35)) = 131.57  (close enough)

Using your original HC I get Z = 132.89

It seems my HC is slightly different than yours.  In the 249 vol 3, using  LHA = 315, DEC = 15, APLAT = 40 contrary,    I found HC = 20:54,  d = -49,  Z = 133.
Using table 5 I found 'd' correction to be -33... So 20:54 - 00:33 = 20:21 which is eq to 20.35

good luck shipmate
joe

Thank you so much

 I found the mistake

Albi