NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2013 Mar 25, 14:11 -0700
Karl,
The first EP is obtained after an unknown amount of DR. The first R.Fix establishes a position. The second R.Fix position gives enough information to now correct for cross track error. The red DR course is just another way to plot until a position is obtained. Course steered and speed through the water are constant for this example. Course made good and speed made good aren't known until the second R.Fix.
Greg Rudzinski
Re: Fix Maximum Probability Positions
From: John Karl
Date: 2013 Mar 25, 12:29 -0700
Greg,
I'm not sure I understand your running fix plot. It looks like:
Your plotted the 900 EP from your 900 DR by applying a eastward correction (current drift maybe).
Then likewise at 1100 your DR moved eastward again to an EP at 1100, where the 1100 sun line just perfectly matched the 1100 EP.
Am I reading this right?
If so, you gave an example with no estimation error. In which case both the estimated-position running fix and the traditional running fix give identical results.
john K
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