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Sorry to bother you off list Rodney.I sent the 1st one to you and not the
list.
-----Original Message-----
From: Royer, Doug
Sent: Thursday, January 29, 2004 12:06
To: 'Rodney Myrvaagnes'
Subject: RE: Parallactic Retardation


Rodney,yes and no to what you wrote below.Yes to a partly or full moon
providing a visible horizon 20 or so degrees on either side of the
moons'azimuth.No to not being able to measure altitude at all when the
moons' light is reflected off the surface of the water.
Most quality newer sextants have a lightly shaded polarising shade/shades
and one can get a good horizon even when measureing an altitude closer to or
at the moons' azimuth.Or you can use a combination,depending on the
brightness of the reflected light on the waters' surface,of a number  of the
sextants' shades to get a good horizon to use for measureing either the
moons' or other body's altitude at a time like this.

-----Original Message-----
From: Navigation Mailing List
[mailto:NAVIGATION-L@LISTSERV.WEBKAHUNA.COM]On Behalf Of Rodney
Myrvaagnes
Sent: Thursday, January 29, 2004 10:49
To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM
Subject: Re: Parallactic Retardation


On Thu, 29 Jan 2004 14:40:16 +0000, George Huxtable wrote:

>
>It's a poor navigator who could measure Moon altitudes only to a
>quarter-degree, though special circumstances may arise, such as measuring a
>Moon's altitude at night above a shimmering horizon that's lit only by that
>Moonlight.
>
I think the reflection of the moon obliterates the horizon in that
direction and you can't measure the altitude at all. However, people
who have done it more than I tell me that a full moon can provide a
visible horizon for star sights away from the moon's azimuth.

.

Rodney Myrvaagnes   NYC
J36 Gjo/a


"Curse thee, thou quadrant. No longer will I guide my earthly way by thee."
Capt. Ahab

   

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