NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Help with Lunar distance.
From: Jeremy C
Date: 2010 May 13, 10:43 EDT
From: Jeremy C
Date: 2010 May 13, 10:43 EDT
Don't get down on poor Jupiter. I took a Jupiter lunar on the 6th of
May with a bit more Ds (40 degrees or so) and got less than 30 seconds of time
error.
Using the Stark Tables is a trip. I don't carry them with me to sea,
but still use them on occasion at home to remind myself how much i don't like
using tables for Lunars. To be fair, I sometimes do the same with HO 229
for LOP's. I am fine with using the NA, but don't much like reduction
tables. I much prefer calculators and computers to do the math for
me.
Jeremy
In a message dated 5/10/2010 3:26:14 A.M. Bangladesh Standard Time,
pw.jackson@xtra.co.nz writes:
Thanks George i will look into the apparent altitude difference. For my next Lunar I will use another body.
--- On Mon, 10/5/10, George Huxtable <george@hux.me.uk> wrote:
From: George Huxtable <george@hux.me.uk>
Subject: [NavList] Re: Help with Lunar distance.
To: NavList@fer3.com
Date: Monday, 10 May, 2010, 9:08 AM
Quite a lot seems wrong here. From that given location of 36º 48'S, 174º
46'E (somewhere near Hamilton, NZ?), at 18h 15m 52s GMT on Greenwich date 9
May 2010, my Skymap program tells me that the apparent altitude of the
Moon's centre is 33º 54.8', not 20º 33.9', and that of Jupiter to be 39º
52.2, not 22º 02.6.
Why do we disagree so greatly? Have the correct position/date/time been
entered into Paul's navigator program? Or by me, into mine?
By the way, those are not ideal circumstances for taking a lunar. With such
a small lunar distance, it can happen that the body sighted is way off the
direction of travel of the Moon through the star background, as it is in
this case. That detracts somewhat from the accuracy of a lunar. However,
Paul's difficulties are more serious than that.
George.
contact George Huxtable, at george@hux.me.uk
or at +44 1865 820222 (from UK, 01865 820222)
or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
----- Original Message -----
From: "Paul Jackson" <pw.jackson@xtra.co.nz>
To: <NavList@fer3.com>
Sent: Sunday, May 09, 2010 8:23 PM
Subject: [NavList] Help with Lunar distance.
I took a Lunar distance in position - 36 48.0 S - 174 46.0 E @ 9 Days 18
hours 15 min 52 sec on the 9th of may 2010.
Calculated Alt moon 20 33.9
Calculated Alt Jupiter 22 02.6
Distance near limb moon & Jupiter = 7 20.8
My Navigator software gives me a lunar time of 2:57:42 GMT how can this
be, can you guys at Nav List Help.
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