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.