NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: A celestial navigation problem
From: Stan K
Date: 2011 Nov 17, 13:51 -0500
From: Stan K
Date: 2011 Nov 17, 13:51 -0500
Greg,
As far as index error/correction goes, I tried to make it as "difficult" as possible for the students. The limb reading was between 0º and -1º, so it was definitely "off the arc". The micrometer drum reading was 58.7', so the index error was -60' + 58.7' = -1.3', for an index correction of +1.3'. I'm not sure if I can increase the clarity without giving it away, e.g. making it "on the arc". Any ideas?
It was a lower limb observation, as stated in the third paragraph of the problem.
I teach a diagram similar to yours, different only in the fact that I show only the half of the circle above the horizon. In fact, in my solution i say "Use a half diagram or similar tool to do this."
Thanks for your input.
BTW, are you going to make it to the Nav Weekend this year, or are you going to visit us electronically again?
Stan
As far as index error/correction goes, I tried to make it as "difficult" as possible for the students. The limb reading was between 0º and -1º, so it was definitely "off the arc". The micrometer drum reading was 58.7', so the index error was -60' + 58.7' = -1.3', for an index correction of +1.3'. I'm not sure if I can increase the clarity without giving it away, e.g. making it "on the arc". Any ideas?
It was a lower limb observation, as stated in the third paragraph of the problem.
I teach a diagram similar to yours, different only in the fact that I show only the half of the circle above the horizon. In fact, in my solution i say "Use a half diagram or similar tool to do this."
Thanks for your input.
BTW, are you going to make it to the Nav Weekend this year, or are you going to visit us electronically again?
Stan
-----Original Message-----
From: Greg Rudzinski <gregrudzinski@yahoo.com>
To: NavList <NavList@fer3.com>
Sent: Thu, Nov 17, 2011 1:19 pm
Subject: [NavList] Re: A celestial navigation problem
From: Greg Rudzinski <gregrudzinski@yahoo.com>
To: NavList <NavList@fer3.com>
Sent: Thu, Nov 17, 2011 1:19 pm
Subject: [NavList] Re: A celestial navigation problem
Stan,
Your exercise needs clarity regarding index error. Was the observation an upper or lower limb ? Have students diagram the LAN for a visual (see link).
Greg Rudzinski
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