07-19-2018, 11:02 AM
Joe,
Both of the formulas you mention in the beginning of your post are correct and yield the same result. The Nautical Almanac specifies the second formula as entered in the Casio fx-300ES Plus calculator. The "Sin-1" is the arc-sin key.
Anyone using the second formula should understand that by comparing it to the first formula that the first "asin" (in the first formula) and "Sin-1" in the second formula are the same thing.
To get the Hc answer correct you might do it this way;
Get the sin of Ap Lat.
Get the sin of Dec.
Multiply those two answers together and write the result down (call the product "A").
Get the cos of Ap Lat.
Get the cos of Dec.
Get the cos of LHA
Multiply those 3 answers together (call the product "B")
Add "A" and "B" together (call the sum "C")
Get the Arc-Sin of "C"
That answer will equal Hc
Craig
Both of the formulas you mention in the beginning of your post are correct and yield the same result. The Nautical Almanac specifies the second formula as entered in the Casio fx-300ES Plus calculator. The "Sin-1" is the arc-sin key.
Anyone using the second formula should understand that by comparing it to the first formula that the first "asin" (in the first formula) and "Sin-1" in the second formula are the same thing.
To get the Hc answer correct you might do it this way;
Get the sin of Ap Lat.
Get the sin of Dec.
Multiply those two answers together and write the result down (call the product "A").
Get the cos of Ap Lat.
Get the cos of Dec.
Get the cos of LHA
Multiply those 3 answers together (call the product "B")
Add "A" and "B" together (call the sum "C")
Get the Arc-Sin of "C"
That answer will equal Hc
Craig