NavList:

----- Original Message -----

From: Anabasis75@aol.com

To: NavList@fer3.com

Sent: Sunday, June 15, 2008 2:11 AM

Subject: [NavList 5454] Re: Exercise #15 CORRECTION

No you didn't do anything wrong, I did.  I had a typo with the Latitude.  The Latitude is 15deg 14.0' North for departure.   That will give you a better answer.

 

Sorry about that.

 

Jeremy

 

In a message dated 6/15/2008 6:33:28 A.M. West Pacific Standard Time, menga@polito.it writes:

Jeremy,
On my account at 14°14' N (the course is due west, so no change of latitude)
on the meridian passage the 10-6-2008 (decl. 23° 1.91'N) the height of the
sun was 81°12.10', taking into account all corrections Hs should be almost
1° lower than yours. Did I do something wrong?
Giuseppe
----- Original Message -----
From: "Anabasis" <jcaoy@yahoo.com>
To: "NavList" <NavList@fer3.com>
Sent: Saturday, June 14, 2008 10:26 AM
Subject: [NavList 5443] Exercise #15 Day's Run (almost)



Exercise #15  Day’s Run (almost)

There has been some request from members of the group to have an “old
school” exercise where “DR’s” are actual dead reckoning positions and
not GPS fixes; giving us a bit of ambiguity as to where the vessel was
at the time of the sight.  This exercise should fit that description.
The scenario is departing anchorage and then heading out to sea, where
position and other celestial checks will be done throughout the day.
The only given position will be the departure point, and all sights
will be based on the previous reductions and running DR tracks.
This scenario is the exact trip we made on 10 June 2008 from
departure until the end of my evening watch at 20h 00m.

For all sights, height of eye is 106 ft, Index error is 0.0.  All
times are local zone time, and the ship is keeping  ZD-10.  The local
date is 10 June 2008.

A ship takes departure from the Saipan anchorage at 9h 00m local
time.  Position is fixed by visual and radar LOP’s and is determined
to be Lat 14deg 14.0’ N; Longitude 145deg 38’ East.  The ship steams
on a course of 270 deg True at making turns (engine speed) for 12.0
knots.

At 10h 25m 59s, a lower limb observation of the sun is made.  Hs is
62deg 22.4’.  Temp is 85deg F Pressure is 1010 MB.

At 12h 19m LAN is observed.  The Hs of the lower limb of the sun is
82deg 06.0’.  Temp is 98 deg F Pressure is 1010 MB.  Soon after LAN,
the navigator sees that the moon has risen and takes an observation of
the upper limb of the moon.  Hs is 6deg 20.8’ at 12h 23m 20s.
Determine a running 12h 00m fix (noon position).  Also determine
distance run as well as course and speed made good since departure.

At 16h 03m 42s a PM Azimuth of the Sun is observed on the starboard
gyro repeater.  The sun’s observed bearing is 286.4 degrees PGC.  The
course PGC is 273.5 degrees, Variation from the chart is 1.3 degrees
East.  Course per magnetic steering compass is 286.0 degrees.
Determine Gyro error and Deviation on this heading.

At 1645 the ship alters course to 180 degrees true, maintaining 12.0
knots.

At 17h 25m 20s, a lower limb observation of the sun is made.  Temp is
95deg Pressure is 1010MB. Hs is 18deg 55.6’

Star time approaches, determine sunset, time of stars, determine LHA
of Aries, and select stars to be shot.

Around 18h 15m, the moon approaches Meridian Transit (LAM).  The
following data is collected:
Moon UL: Hs 78deg 34.9’ at 18h 11m 58s
Moon UL: Hs 78deg 37.5’ at 18h 13m 03s
Moon UL: Hs 78deg 37.2’ at 18h 13m 41s
Moon UL: Hs 78deg 36.4’ at 18h 14m 20s
Moon UL: Hs 78deg 37.2’ at 18h 14m 46s
Moon UL: Hs 78deg 36.1’ at 18h 15m 27s
Moon UL: Hs 78deg 35.7’ at 18h 16m 12s
Moon UL: Hs 78deg 35.4’ at 18h 16m 42s
Moon UL: Hs 78deg 34.2’ at 18h 17m 10s
Moon UL: Hs 78deg 33.4’ at 18h 17m 42s
Sun UL: Hs 7deg 27.2’ at 18h 18m 33s
Sun UL: Hs 7deg 15.8’ at 18h 19m 17s
Sun UL: Hs 7 deg 08.8’ at 18h 19m 50s
Sun UL: Hs 7 deg 01.2’ at 18h 20m 27s
Determine the 18h 15m fix.

As the sun was near setting, an amplitude was observed on the
Celestial Horizon.  The sun’s bearing was 294.7 degrees.  The ship was
steering 180 PGC, 168 per magnetic compass, and the variation off of
the chart was 1.3 degrees East.  Determine Magnetic Deviation at this
heading.

PM star time was poor with clouds and a hazy horizon.  Only two bodies
were observed.  Temp was 84 deg F, pressure is 1010MB.
Arcturus was shot at 19h 20m 51s Hs is 60deg 34.0’
Dubhe was observed at 19h 13m 53s  Hs is 41deg 58.6.
Determine the 1900 star fix.

Have fun
Jeremy



--~--~---------~--~----~------------~-------~--~----~
Navigation List archive: www.fer3.com/arc
To post, email NavList@fer3.com
To , email NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---

   

Reply