A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Noell Wilson
Date: 2017 Jun 28, 18:19 -0700
Ok. I worked the LOP's using the numbers given. With a 10" slide rule, I hope to be close but I was 30 miles or more off and the conversation turned to hidden errors in the problem.
Let's try this in the search for the errors. Did our navigator get Some of the star info using one UT instead of the time for each shot?
Andres info followed by that from USNO using the exact time: * for differences
Date UT Star GHA Dec Ho
20/02/1990 06:39:15 Sirius 148.5701201 -16.70358745 57.97742057
148-34.2 * 16-42.3S. Hc 57-45.8 * using correct times
20/02/1990 06:40:54 Capella 171.1717579 45.99316887 32.467935
171-10.3. 45-59.7. Hc 32-15.0* using correct times
20/02/1990 06:42:34 Pollux 134.3985921 28.05125701 30.29880443
134-39.0 * 28-03.1 29-57.5* using correct times
The GHA of Sirius changed with the time.
The GHA of Capella didn't - I'm not sure why not. Maybe he only used one incorrect time for Sirius.
Is GHA of Pollux a typo?
All Hc's changed and are 20' to 30' lower. I'm not sure why.
Perhaps the navigator used 06:42:34 for Sirius when he should have used 06:39:15 UT.
Perhaps the navigator copied the GHA of Pollux as 134.39 when it should be 134-39.0.
Obviously, I don't know where we're heading or what the problem is supposed to be. The seven digit precision angles don't match with the chance of a basic error.