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Re: The Rude Star Finder and teaching stars
From: Jeremy C
Date: 2010 Nov 14, 08:14 EST
From: Jeremy C
Date: 2010 Nov 14, 08:14 EST
Alan wrote:
2. Re the 5 star fix mentioned, I've shot 3 body fixes, ending up
with a triangle, sometimes a small triangle, other times a not so small
trialgle, this standing on the beach. What sort of figure might one get with a 5
body (star) fix, a pentagon?
------
When you start plotting lots of lines like this, the plotting sheet
looks pretty crowded. If have a great round where there is little
individual LOP error and the scale is pretty small, then the pencil makes a nice
dot on the sheet. If you have a less than stellar round, you start getting
multiple triangles which actually confuses the matter of your
position.
You can do all sorts of computer analysis of probability , with the
95% ellipses and the like, but in the hurry up real world out here, you choose
which triangle looks or feels the best and put your fix down there. In the
middle of the ocean, that mile or two difference between the various triangles
and intersections isn't going to make any difference at all.
Personally, I find the plotting process of many stars tedious
and prone to graphical error, especially using AP tabular methods. These
days I shoot a round of stars, plug the data into the software, and it gives me
the mathematical most probable location of my ship and spits out a Lat and
Long. I then transfer the Lat and Long from the computer and scribe my fix
surrounded by a circle and label it "* fix @ `time`" This is quick,
accurate, and neat.
Jeremy
