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Subject: How to choose among position lines?
From: Federico Rossi (fedeastro.rossi@XXX.XXX)
Date: Wed Jun 11 2003 - 13:08:08 EDT
Hallo everybody,
I want to submit you a doubt I often encounter when I draw position lines to find the position.
Usually, in the Italian merchant marine they used to plot 4 position lines, aproximately 90° with respect to each other, and this configuration doesn't leave space to doubt when it's time to draw the bisecants in order to reduce the systematic errors.
The Americans used to be even more practical and adopted 3 lines spaced 120° (obviously this in the ideal condition when you can choose which bodies to shoot).
In "100 problems in Celestial Navigation", which I consider a very good exercise book and I advise to everybody, instead the author often uses 5, 6, 7 or sometimes even 8 bodies, differently spaced in azimuth. In this cases, are there general criteria to choose the lines to use (since the choice can bring to significantly different positions)?
Thanks,
Federico Rossi
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