for the day preceding, if east longitude. Using the daily difference between the times for the nearest tabular latitude, and the longitude, enter Table II of the Almanac "Tables for Interpolating Sunrise, Sunset, etc." and take out the correction. Apply this correction to the LMT of moonrise or moonset at the Greenwich meridian on the given date to find the LMT at the position of the observer. The sign to be given the correction is such as to make the corrected time fall between the times for the two dates between which interpolation is being made. This is nearly always positive (+) in west longitude and negative (-) in east longitude. Convert the corrected LMT to ZT.
With the given information in the following. problem, determine the zone time of moonrise.
At 2100 zone time, on the 30 January 1981, your DR position is LAT22° 26.0'S, LONG 158° 50.1'E. You are steering a course of 115 T at a speed of 15.5 knots. What is the zone time of moonrise?
A.0015 B.0036 C.0057 D.0134
Procedure Follow these steps to calculate the zone time of moonrise.
1. Enter "The Nautical Almanac" and locate
the page that correspond to the date you are using.
2.
Using a universal plotting sheet determine the DR position (latitude & longitude) of your
ship at the approximate time of moonrise [ 00 58 ].
Lat. 22° 52.2'S Long. 159° 46.3'E
Select the proper section.
IF you need ... THEN use the ...
moonrise upper section.
moonset lower section.
JAN 1981
30 29
Lat. MR MR
3.
Go down the latitude column and locate the tabulated latitudes that bracket your DR latitude and extract the latitudes and moonrise on the 30th and 29th since it is in
for the day preceding, if east longitude. Using the daily difference between the times for the nearest tabular latitude, and the longitude, enter Table II of the Almanac "Tables for Interpolating Sunrise, Sunset, etc." and take out the correction. Apply this correction to the LMT of moonrise or moonset at the Greenwich meridian on the given date to find the LMT at the position of the observer. The sign to be given the correction is such as to make the corrected time fall between the times for the two dates between which interpolation is being made. This is nearly always positive (+) in west longitude and negative (-) in east longitude. Convert the corrected LMT to ZT.
With the given information in the following. problem, determine the zone time of moonrise.
At 2100 zone time, on the 30 January 1981, your DR position is LAT22° 26.0'S, LONG 158° 50.1'E. You are steering a course of 1150 T at a speed of 15.5 knots. What is the zone time of moonrise?
A.0015 B.0036 C.0057 D.0134
Procedure Follow these steps to calculate the zone time of moonrise.
STEPS
1. Enter "The Nautical Almanac" and locate
the page that correspond to the date you are using.
2.
Using a universal plotting sheet determine the DR position (latitude & longitude) of your
ship at the approximate time of moonrise [ 00 58 ].
Lat. 22° 52.2'S Long. 159° 46.3'E
Select the proper section.
IF you need ... THEN use the ...
moonrise upper section.
moonset lower section.
JAN 1981
30 29
Lat. MR MR
3.
Go down the latitude column and locate the tabulated latitudes that bracket your DR latitude and extract the latitudes and moonrise on the 30th and 29th since it is in east longitude. If it was west longitude, we would have used the 31st data. 4.Determine the difference between tabulated latitudes and the time values .
S 20° 0058 - 0018
S 30 0044 - 0007
S 10 14m - 11m
5.
Determine the ratio of change in time for each degree of change of latitude by dividing the latitude difference into the time difference.
14 min / 10° = 1.4 min
11 min / 10° = 1.1 min
