+kurchian Posted January 23, 2015 Share Posted January 23, 2015 Does is make any difference if my GPSr is set on Magnetic North or True North when attempting to project a waypoint of about 1000 feet? What is the best setting for geocaching? Quote Link to comment
+BikeBill Posted January 23, 2015 Share Posted January 23, 2015 Someone correct me if I'm wrong, but I think you want True North. Quote Link to comment
+Walts Hunting Posted January 23, 2015 Share Posted January 23, 2015 Actually it depends on the cache as to which you want. Unless stared otherwise use true but I have seen a few specify magnetic. How much depends on where you live and the local declination. Ten degrees at 1000 is 175. Quote Link to comment
Forkeye Posted January 23, 2015 Share Posted January 23, 2015 (edited) If you project a waypoint ie: create one it wont make a difference in the direction you head but you will get a different bearing depending on your setting, true or magnetic,and you must state what you used if telling someone else, but if you use someone elses projection then you must use the correct setting to be on the correct coarse, just as you would with a real compass. You can work in either magnetic or true settings or stay in the setting you like and convert. But the easiest way is to just use the specified setting for the bearing given or used. If you don't you will be going off coarse. You must always specify the bearing as true or magnetic unless everyone accepts that one is the correct/ proper one. Edited January 23, 2015 by Forkeye Quote Link to comment
+ecanderson Posted January 23, 2015 Share Posted January 23, 2015 Does is make any difference if my GPSr is set on Magnetic North or True North when attempting to project a waypoint of about 1000 feet? What is the best setting for geocaching? Unless cache owner has specified use of magnetic (which some do, just to make life 'interesting') you should always assume true. The difference in where you'll wind up over the course of 1000' depends upon where you live since the difference between mag/true varies all around the world. Quote Link to comment
+Capt. Bob Posted January 24, 2015 Share Posted January 24, 2015 As a CO you should always use True North. Compass needles do not point to Magnet North as many think. Compass needles align themselves to the local magnetic lines of flux (isogonic lines). These lines can vary due to local influences, from a simple steel spring in the carabiner holding your GPSr to geological anomalies deep within the earth. True North will never vary. If it does we got bigger issues. Quote Link to comment
+ecanderson Posted January 24, 2015 Share Posted January 24, 2015 As a CO you should always use True North. Compass needles do not point to Magnet North as many think. Compass needles align themselves to the local magnetic lines of flux (isogonic lines). These lines can vary due to local influences, from a simple steel spring in the carabiner holding your GPSr to geological anomalies deep within the earth. True North will never vary. If it does we got bigger issues. Nothing prevents a CO from being 'clever' and specifying the use of magnetic north in the cache instructions (I've found several done this way). Of course, a few years later, you may want to consider what the declination was at the time the cache was placed - especially if the next waypoint is a fair distance away. An easy approach when you encounter a magnetic heading is to modify the heading angle by the appropriate declination and continue to use true on the device rather than switching to magnetic. Hey - a cacher might actually LEARN something in the process. That said, unless magnetic is specified, one should assume true in any description or directions. Quote Link to comment
Forkeye Posted January 26, 2015 Share Posted January 26, 2015 I guess I am old school and come from a scientific and technical back ground , mean what you say and say what you mean... state what units you are using.. .otherwise you are bush league, and nobody knows wtf you are talking about! We all know about assumptions and what the ramifications are, sorry for the rant. Quote Link to comment
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