Maritime Celestial Logarithm Tables Mastery

Maritime Celestial Logarithm Tables Mastery: Two exercises of the calculated height (Hc) of the sun with logarithm tables and solution.


Maritime Celestial Logarithm Tables Mastery,example of calculating Hc(calculated height) with the logarithm tables
example of calculating Hc(calculated height) of the sun with the logarithm tables
decorative image: tug towing a merchant navy vessel

The five tables:

Maritime Celestial Logarithm Tables Mastery, image of the five tables needed for calculating the height of the sun at sea1
Maritime Celestial Logarithm Tables Mastery, image of the five tables needed for calculating the height of the sun at sea

This section serves as an additional feature on my website, and it’s crucial to highlight that I don’t endorse starting with this particular method.

Here, I introduce a well-established celestial navigation technique that involves utilizing logarithm tables.


To initiate from the start, it is crucial to begin with the La Rochelle exercise, which includes all the fundamental concepts.

decorative image: sling handling for stowage.(old picture)

Celestial Logarithm Tables Mastery: SEE FIRST

the fully worked out example !

Author image: Laima Gütmane

Maritime Celestial Logarithm Tables Mastery

exercise 1

entries L D and P

The entries obtained in the first part of the worksheet are necessary to find the calculated height (Hc):

L = 19° 03′ N ( D.R. latitude)

D = 21°10′,5 S (Declination of the sun)

P = 7°21′,9 (NW) (polar angle)

(latitude North and sun in the West)

Celestial Logarithm Tables Mastery  part of worksheet

Maritime Celestial Logarithm Tables Mastery:

Step 1

Celestial Logarithm Tables Mastery  part of worksheet
Celestial Logarithm Tables Mastery same name/not same name

First the two entries obtained from the worksheet:

L = 19° 03′ N // D = 21°10′,5 S

L =

D =

__________________

(L /D) =


To clarify see the four examples same name/not same name


Maritime Celestial Logarithm Tables Mastery:

Step 2

Now we need the three entries obtained from the worksheet:

L = 19° 03′ N // D = 21°10′,5 S

P = 7°21′,9 (NW)

Celestial Logarithm Tables Mastery  part of worksheet

1(T 1 ) LOG COS L =

2(T 1 ) LOG COS D =

3(T 2 ) VERSINE P =

_________________________+

LOG 2e Term =


Maritime Celestial Logarithm Tables Mastery:

Step 3

Celestial Logarithm Tables Mastery  part of worksheet

First the entries: (L/ D) obtained in step 1

The entry log 2e term obtained in step 2 is then transformed to the natural 2e term using Table 4 (logarithms of whole numbers).

(T 3) COS (L / D) =

(T4 ) Nat 2e T =

__________________________⎼

SIN Hc =


Here an example of Table 4 (logarithms of whole numbers) to transform log 2e T to Nat 2e T


Step 4

the entry sin Hc obtained in step 3

(T 5) Hc =


Maritime Celestial Logarithm Tables Mastery:

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The second exercise

entries L D and P

L = 31° 29′,5 N

D = 23° 18′,1 N

P = 32° 23′,8 NE


Celestial Logarithm Tables Masterypart of worksheet

step 1

Celestial Logarithm Tables Mastery part of worksheet

Here the two entries obtained from the worksheet:

L = 31° 29′,5 N; D = 23° 18′,1 N

L =

D =

__________________

(L /D) =


In addition 4 examples same name/not same name


Maritime Celestial Logarithm Tables Mastery

Step 2

First the three entries obtained from the worksheet:

L = 31° 29′,5 N D = 23° 18′,1 N

P = 32° 23′,8 NE

Celestial Logarithm Tables Mastery part of worksheet

1(T 1 ) LOG COS L =

2(T 1 ) LOG COS D =

3(T 2 ) LOG VERSINE P =

__________________________+

LOG 2e Term =


Celestial Logarithm Tables Mastery:

Step 3

Celestial Logarithm Tables Mastery part of worksheet

First the entries: (L/ D) obtained in step 1

The entry log 2e term obtained in step 2 is then transformed to the natural 2e term using Table 4 (logarithms of whole numbers).

(T 3) COS (L / D) =

(T4 ) Nat 2e T =

__________________________

SIN Hc =


Here an example of Table 4 to transform log 2e T to Nat 2e T


Step 4

the entry sin Hc obtained in step 3

(T 5) Hc =

decorative image : sailor's pipe

Maritime Celestial Logarithm Tables Mastery: short summary

In this course, you will find a total of four exercises from the logarithm tables, with the necessary pages of the tables and solution included. .

Once you have gone through them and become familiar with them, you can test your skills on the seven remaining exercises. You need to purchase the PDF answer files in the store and they come with the full download version of the tables.

I printed these tables along with the azimuth tables, using only one XL cartridge, or you can check with your local printing house.This is an exceptional tool, but you need to be very organized.

Cloud Ocean And Moon, Author image: Jason Efstathiou