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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Latitude AND Longitude by Noon Sun+GPS
From: Kieran Kelly
Date: 2004 Jan 26, 10:27 +1100
From: Kieran Kelly
Date: 2004 Jan 26, 10:27 +1100
Jared Sherman wrote: "I have to wonder, if one is someplace so overgrown, or so deep in the canyons, that one cannot get a useable GPS view of the sky, just how much use a sextant will be? If the GPS can't see the sky, how is the sextant going to do any better? Sniping through the treetops at the few bodies that will only be present in cloudless skies?" Yes Jared, that is very true. I have tried to use sextants in inland Australia on many occasions and in even variable scrub cover, it becomes very difficult. You can sometimes see the glimmer through the trees but it becomes tedious moving the artificial horizon around. Impossible if there is a breeze moving the leaves. What tends to happen is that you shoot stars of a very high altitude. In canyons and gorges it is not so bad. You can wait for bodies to pass over the gorge walls and take a shot. Often you are looking down the gorge. this will give an LOP which will intersect (usually) the gorge or river feature marked on a map. This is like having one LOP, a gorge, river etc already marked on the map, over which you lay an LOP derived from CN. The only problem with this is you have to know exactly which gorge or river you are on. In multi stream situations or very fractured gorge country this can become debatable. The great advantage we have in this country is that the dry season skies are always cloudless. You can go for months and not see a cloud. However before GPS, before the sextant, before Hooke's quadrant and the Astrolabe there was that prince of instruments - the compass. No matter the scrub cover, no matter how deep the gorge, during the sweltering noon or by the light of a bright morning star it will never let you down. It's always switched on and yet never runs out of batteries. I never set foot out of doors in this country without my Francis Barker prismatic as I feel with it I will never get lost. However I see people from here and abroad heading into the wilderness loaded down with GPS gear who couldn't tell east or west from Orion's belt if it fell on their head. Kieran Kelly Sydney Australia -----Original Message----- From: Navigation Mailing List [mailto:NAVIGATION-L@LISTSERV.WEBKAHUNA.COM]On Behalf Of Jared Sherman Sent: Monday, 26 January 2004 9:36 AM To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM Subject: Re: Latitude AND Longitude by Noon Sun+GPS
