How to Reduce a Sunline Using Pub 229, Continued
Pub 229 Naut Alm
Apply altitude corrections to find.
Enter the GHA hour value from the
Enter the minutes and seconds value from
the Nautical Almanac.
Add GHA(h) and Increments (m/s).
ENTER SHA for stars or planets only.
STARS and PLANETS
a Long (+E, -W)
Enter the assumed DR longitude to arrive at
(+ - 360° if needed)
an even degree of LHA, add east and
LHA= Total GHA + (v/v or SHA for star
and planets) +E or -W DR Long.
Enter the tabulated declination for 07 hours
N 4° 17.3'
on the Sun column from Nautical Almanac.
d# / D Corrn
The d# is found at the bottom of the Sun
+0.6 / +0.3'
Dee column; in this case it is +1.0. It is
assigned a + because dec is increasing.
same or contrary
The D corr is found on the Increments and
Corrections page for 15m38s. Look under
the v or d column for the d# (1.0) and
record the Corrn value (0.4). The D Corrn
assumes the same sign as the d#.
Apply the D Corrn to Tab Dec
Enter the whole degree of latitude and
determine if it is named (N or S) as True
Dec. In this case lat. is N and Dee is N, so
it is same.
N 4° 17.6'
N 37° same
We have finished stages 2 and 3 and can move on to our final stage.