|Note on Compass Boxing vs True Bearings #1160|
Back To Discussion List Written: 2004.05.23 by: Mike Cleven
I've been meaning to write this for a while but never seem to get to it; so since Basemap's down this fine Victoria Day Sunday and won't be back up until Tuesday (probably) I'll spend a few minutes on this...
For anyone who's noted my various subpeak listings and compass directions for saddles, I've been trying to be more or less specific on the exact direction of the various subpeaks and saddles. But, alas, I must admit to being more than a bit idiosyncratic about the compass boxing - as anyone who took compass boxing in boy scouts or sailing lessons or whatever. Mea culpa....
The issue is that my method of compass boxing is not the traditional one, and I realize in retrospect this may cause a bit of confusion; The reason being that the traditional way of specifying lesser points of the compass - something other than N, S, E, W, NE/NW, NNE/NNW etc - is itself a bit confusing; so I "adjusted" it to something that seems more logical. But logic isn't tradition, and for those familiar with conventional compass boxing I realize now my compassings aren't that understandable; namely, and specifically, what I mean by "WxS" isn't what traditional compass boxing means by it. I mean a little bit south of west; in true compass-boxing WxS actually means a few degrees south of west. Similarly NNWxN and other usages I've coined; in my "system" the second direction is the auxiliary one; in traditional boxing the first one is. So NWxN is a few degrees W of WxN in the "real" system, but in mine it means a few degrees N of NW, but not quite NNW. Confusing? Yeah, for me too, and I confess I haven't always been accurate; only "relative".
So now I'm nearing the end of charting all the obscure ranges and summits that Basemap has made it so easy to find, if not to catalogue, I'm realizing I have to go back and fix all the subpeak and saddle directions. I know that a general N/W/S/E or NW/SE is what was expected, and not even WNW/ESE or anything like that, which may be fine for climbers and casual hikers; but I know that anyone doing orienteering or anything more specific needs more precision. So in watching Basemap's various directional readings, all of which use "true bearing" (degrees, as opposed to compass boxings) it's occurred to me that maybe that's a more useful paradigm for the "fixing" of the directions I've already put in. For one thing, compass boxing ALWAYS has to be reckoned within the difference between geographic north and magnetic north, as far as anyone actually using a compass goes. True bearing, for those that understand it, makes a lot more sense as it relies on absolute geographic direction.
i.e. geographic north is zero degrees, geographic south is 180 degrees; west is 270, east is 90, and so on. The comparison maybe is between the imperial system of measure and the metric. What I'm proposing is that in going back and fixing the thousands of directional indications I've already put in the best system might be to use true bearing, instead of ANY conventional compass bearings; or I just get rid of obscurites like "WxS" and replace them their simplest forms, i.e. in that case "W", with only the eight main points of the compass (N/NW/W/SW/S/SE/E/NE) or maybe the full thirty-two (N/NNW/NW/WNW/W etc), with none of the little xN, xW etc involved.
I think "true bearing" is the way to go, and when plotting subpeaks and saddles the info's right there in Basemap's directional measuring tool, ready to be transcribed.
Just offering this up for discussion. Unfortunately there's no way to globally convert all the directions already put in, so I'll have to go back and do it all by hand. I didn't want to change systems until I'd finished plotting things; now that that's almost done I thought it was time to field the idea/question.