NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Technique question
From: Doug Royer
Date: 2003 May 19, 17:05 -0700
From: Doug Royer
Date: 2003 May 19, 17:05 -0700
O.K.,let me explain better what I was asking earlier.I wasn't referring to takeing altitudes to the visible horizon.That is not the concern here.The concern is about the distance angle between the Moon and another body.Everyday at sea I check the Ie against the semi-diameter of the Sun.All other errors are checked periodically as the Tamaya's error has been consistantly 0.1'- 0.2' off the arc for eons under many differant conditions.Checking the Moon's semi-diameter accomplishes the same thing.I check for the true horizon as noted below during every observation.When takeing the distance measurements of the bodies I swung the arc.When Jupiter or the star touch the Moon's edge I took the reading.In the awkward position the sextant was in to get the readings maybe the objects were off center in the scope.I don't know if that would give a consistant error or not.5'of error is huge.I'll be on the alert for it from now on.My question about under what atmospheric conditions you guys observe Lunars remains unanswered.Is this a fair weather(clear skies) proceedure or have others accomplished it under adverse conditions,not that the conditions I had were all that adverse? -----Original Message----- From: Philip Ouvry [mailto:ranch.flamingo@INFONIE.FR] Sent: Monday, May 19, 2003 12:55 To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM Subject: Re: Technique question Many books warn of a possible false horizon under the moon. However by panning left and right it is usually possible to determine the position of the true horizon. With experience if you can see the edges of the moon then it should be feasible to take sights. HTH Philip Ouvry
