STEP 1
Using GMT, and Greenwich date of your observation, enter the Nautical Almanac and record the tabulated hourly value of GHA and tabulated declination in your format.
STEP 2
At the foot of each GHA sub-column for the PLANETS, a number is found. This number is the "v" correction. Record this in your form. The "V" correction is always plus (+) for GHA except in the case of the inferior planet Venus, which has an orbit inside the earth's orbit. Its apparent motion westward, as compared with the sun's motion, shows that Venus has a numerically lesser, relative speed. When its correction should be subtracted, the letter "V" will be prefixed by a minus sign. The purpose of the "V" correction is to simplify interpolation and to keep tabulated values at a minimum, and makes possible the use of the GHA value for minutes and seconds as tabulated for the sun.
STEP3
Record the "d" correction for the declination.
STEP 4
EXAMPLE : Turn to the yellow pages of the Nautical Almanac and find the 15 minute page. Enter with lets say 54 seconds. Then under the Sun and Planets column find the increase in the Venus GHA since the last tabulated (hourly) value, this is your M&S correction and enter this in your format.
While on the minute page under the 'V or "d" correction column, find the "v" on the left hand side. This is equal to 0.2', enter this in your format and in this case it is added. At the same time, find your "d" 0.6 = (0.2) enter this in your format. This will be the declination (dec) of Venus at the time of sight.
STEP 5
Add the GHA, M &S, and "v" correctlon to get the GHA TOTAL; subtract the "d" correction to find the declination of Venus
STEP 6
Bring down your DR longitude end enter it in your form. The rule is:
LHA = GHA + EAST LONGITUDE
LHA = GHA - WEST LONGITUDE
Once you see this on a form it will be easier to see.
