NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: lunars with and without altitudes
From: Frank Reed CT
Date: 2006 Nov 16, 02:24 EST
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to NavList@fer3.com
To , send email to NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---
From: Frank Reed CT
Date: 2006 Nov 16, 02:24 EST
Alex,
In message #1712, you wrote:
"I do not believe that the method is practical.
(Of course an experiment is needed to decide.
But I will be very surprised if it will be shown
that the method can be useful in ANY real situation)."
(Of course an experiment is needed to decide.
But I will be very surprised if it will be shown
that the method can be useful in ANY real situation)."
I found this message confusing since you seem to be referring
to two different discussions that are going on.
You wrote:
"Indeed, the expected accuracy is estimated as 0.5
of a degree in the best case (ideal conditions, ideal
observer, ideal sextant, moon almost in zenith)."
"Indeed, the expected accuracy is estimated as 0.5
of a degree in the best case (ideal conditions, ideal
observer, ideal sextant, moon almost in zenith)."
Here, for example, you seem to be referring to the idea, which I brought up
on the list, of getting a position fix by lunar distances at known GMT
(which we were discussing previously in the thread "Latitude by Lunar
Distances"). And yet you say that the expected accuracy under ideal conditions
is 0.5 degrees which is clearly incorrect that method --flat out wrong. So
did I miss something? Were you talking about something else?
And you wrote:
"And to achieve this degree of accuracy, the method still
requires either altitudes of a DR position within
a degree or so of the true position."
"And to achieve this degree of accuracy, the method still
requires either altitudes of a DR position within
a degree or so of the true position."
Again, can you clarify: what are you talking about here?? What method
requires "either altitudes or a DR position within a degree"?
-FER
42.0N 87.7W, or 41.4N 72.1W.
www.HistoricalAtlas.com/lunars
42.0N 87.7W, or 41.4N 72.1W.
www.HistoricalAtlas.com/lunars
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to NavList@fer3.com
To , send email to NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---