Joe,
As to your question number 2:
HP is particular to Moon observations.
Using the Altitude Correction for the Moon here-
https://thenauticalalmanac.com/Altitude%...20Moon.pdf
Date- June 8, 2018
GMT- 01:00
Moon HP= 56.2 (found in The Nautical Almanac)
Example- Ha= 52° 32' (LL- Lower Limb)
Step- 1
In the table find your Ha range using the top row (for degrees) and side column (for minutes).
Ha (App. Alt) is found to be 52° 45' (located in the column- 50° - 54°) and the row 30'
Step- 2
-While in the column- 50° - 54° drop down to the HP correction area. (the lower portion of the page)
- Look to the left side of the HP correction area and find the HP closest to the HP of 56.2 in the L column.
- In the row of 56.1 you'll find a correction of 3.6 (3.6 minutes of arc) where that row intersects the 50° - 54° column.
- Add the 52° 45' to 0° 03.6' and get- 52° 49' (rounded up)
Now you have the correction for HP of the Moon.
Concerning question 3-
Why is there a combined refraction figure for the Sun (and planets, stars...etc) in the Altitude Correction Table but there is also a separate correction table for refraction found elsewhere?
Here's the Altitude Correction Table-
https://thenauticalalmanac.com/Altitude%...0Table.pdf
- The Altitude Correction Table has all of the necessary corrections (Refraction, Parallax, Semi-diameter) in one figure so you don't have to find them individually. Dip is also included in the Altitude Correction Table but that's one of those figures that specific to your physical position above the water and therefore a variable that can't be included in the, for example, Sun correction figure on the sheet.
The Altitude Correction Table makes it a lot easier to arrive at Ho and saves time.
Does that make sense?
Roland
As to your question number 2:
HP is particular to Moon observations.
Using the Altitude Correction for the Moon here-
https://thenauticalalmanac.com/Altitude%...20Moon.pdf
Date- June 8, 2018
GMT- 01:00
Moon HP= 56.2 (found in The Nautical Almanac)
Example- Ha= 52° 32' (LL- Lower Limb)
Step- 1
In the table find your Ha range using the top row (for degrees) and side column (for minutes).
Ha (App. Alt) is found to be 52° 45' (located in the column- 50° - 54°) and the row 30'
Step- 2
-While in the column- 50° - 54° drop down to the HP correction area. (the lower portion of the page)
- Look to the left side of the HP correction area and find the HP closest to the HP of 56.2 in the L column.
- In the row of 56.1 you'll find a correction of 3.6 (3.6 minutes of arc) where that row intersects the 50° - 54° column.
- Add the 52° 45' to 0° 03.6' and get- 52° 49' (rounded up)
Now you have the correction for HP of the Moon.
Concerning question 3-
Why is there a combined refraction figure for the Sun (and planets, stars...etc) in the Altitude Correction Table but there is also a separate correction table for refraction found elsewhere?
Here's the Altitude Correction Table-
https://thenauticalalmanac.com/Altitude%...0Table.pdf
- The Altitude Correction Table has all of the necessary corrections (Refraction, Parallax, Semi-diameter) in one figure so you don't have to find them individually. Dip is also included in the Altitude Correction Table but that's one of those figures that specific to your physical position above the water and therefore a variable that can't be included in the, for example, Sun correction figure on the sheet.
The Altitude Correction Table makes it a lot easier to arrive at Ho and saves time.
Does that make sense?
Roland