NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: A fluke of 0.0 intercept with Altair.
From: George Huxtable
Date: 2010 Sep 22, 08:42 +0100
From: George Huxtable
Date: 2010 Sep 22, 08:42 +0100
Antoine wrote-
...if we use tenths of arc minutes instead of arc seconds - which has
nowadays become most usual navigational practice -, we could as well use
the Civilian Aviation Format (this the one I am using to enter coordinates
in our Honeywell Flight Management Computers) through entering such
coordinantes as : N3013.2W08152.3
Such format is quite compact. It also eliminates the use of ' (arc minute
symbol) which I sometimes cannot get to show up correctly in the NavList
Forum posts. It can also be easily extended if more significant figures are
required : N30�13'13" W081�52'16" will then show up as N3013.217W08152.267
If using this specific aviation code, the height quoted by Paul would then
have been 4026.2 (or 40�26'2 in its classical transcription) while using
the 40.262 figure would imply decimal degrees (which was you initial and
early guess).
This is just a suggestion and an idea in the air ... What do you think, my
Fellow Maritime Navigators about such an aviation format ?
===================
Response from George-
HORRIBLE! A recipe for misunderstanding and disaster! May be OK for
entering data into a very specific instrument, but not in general
discussion in a forum such as ours, in which all sorts of quantities may
appear. Decimal numbers should mean decimal numbers, without a hidden
sexagesimal intrusion into them, which would take us back into the confused
number-world of the ancient Greeks and the Babylonians.
Presumably, Antoine's format requires 4 digits before the decimal point,
for latitudes (up to 90º), and 5 digits for longitudes (up to 180º). What
about sextant angles, then? Would altitudes (never more than 90º) be
allocated 4 digits? In which case, lunar distances (up to 120º) would
require 5.
If a contributor can't find acceptable symbols for degrees and minutes, he
can always use the appropriate letters, d, m, s. Where's the problem?
George.
contact George Huxtable, at george{at}hux.me.uk
or at +44 1865 820222 (from UK, 01865 820222)
or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
