Minnesota and northwest Ontario have declination close enough to zero as makes no difference. There's a lifetime of outdoor fun to be had thereOr you can buy a compass with declination adjustment, set it properly, and fuhgeddaboudit.
Minnesota and northwest Ontario have declination close enough to zero as makes no difference. There's a lifetime of outdoor fun to be had thereOr you can buy a compass with declination adjustment, set it properly, and fuhgeddaboudit.
Hi folks,
For years I've been touting the importance of map and compass skills as a critical life-preserving tool for navigating in the back country. Yet I recognize that many (most) folks don't possess even a basic understanding of how to use these two items together. To overcome the lack of knowledge, a friend and I started working on a short video over the summer that provides a tutorial on how to use these two items effectively. We're now looking for feedback. We're trying to keep the video short (less than 5 minutes) and sweet. The videos available on Youtube are generally long and wandering, but we want to work within most peoples' attention spans. The audio is really inconsistent (we've added content multiple times), and the ah, talent - if you can call it that - is severely lacking, but we'll fix all that once we're happy with content. Comments from seasoned M&C experts as well as those learning for the first time are enthusiastically welcomed. Remember, we want to keep it short, with critical points only. Video is here. THANKS!
In the land of zero declination, France looks like a interesting hiking destination.Minnesota and northwest Ontario have declination close enough to zero as makes no difference. There's a lifetime of outdoor fun to be had there
Wikipedia/USGS's neat animation of the "wandering" northern magnetic pole: https://en.wikipedia.org/wiki/Magne...netic_Field_Declination_from_1590_to_1990.gif... point toward the mass of molten iron moving around in the earth ... it changes over time, slowly.
Very nice! Clear, concise, and annotated with helpful graphics.
BTW, your target audience for this video is tacitly "eastern North Americans". Perhaps it should be overt because a large segment of the earth's population will be led astray if they add the declination adjustment.
Very nice! Clear, concise, and annotated with helpful graphics.
BTW, your target audience for this video is tacitly "eastern North Americans". Perhaps it should be overt because a large segment of the earth's population will be led astray if they add the declination adjustment.
Here's how I present the Declination problem (when do you add, when do you subtract?) It sounds more complicated than it really is.
If going from map (true north reference) measurement to compass (magnetic north reference) measurement
1. Given an azimuth relative to True North (as would be measured by a protractor directly from the map)
2. Look at the declination diagram for your region (draw one if it is not apparent)
3. Imagine an object of interest and its azimuth in the first quadrant (makes no difference where the object actually is relative to you)
4. Ask yourself:From the diagram, is the magnetic azimuth angle to the object greater or smaller than the true azimuth angle to the object?
5. If the mag azimuth angle is greater, then you will add the declination to the given True N azimuth angle (if smaller then subtract)- this is what you set your compass to, then turn your body to "box the needle" to walk to the field destination.
If going from compass azimuth(magnetic north reference) measurement to map azimuth (true north reference) measurement
1. Given the magnetic azimuth of an observed object relative to Magnetic North (as would be measured in the field directly with a magnetic compass)
2. Look at the declination diagram for your region (draw one if it is not apparent)
3. Imagine an object of interest and its azimuth in the first quadrant (makes no difference where the object actually is relative to you)
4. Ask yourself: From the diagram, is the true azimuth angle to the object greater or smaller than the magnetic azimuth angle to the object?
5. If the true azimuth angle is smaller, then you will subtract the declination from the magnetic azimuth angle (if larger then add) - turn the bezel of your compass to this angle to use it as a true north protractor on the map.
(In most cases the Grid north lines pre-drawn on topo maps are usually within 2 degrees of TN, practically accurate enough for most to use as true TN reference - or you can manually mathematically adjust for Grid Dec in a similar manner)
Simplified: From the dec diagram: "Which angle is larger?" add or subtract appropriately.
Alternatively, you can draw magnetic north lines directly on the map as reference lines and never have to worry about adding or subtracting declination again.
Yikes. I have a popsicle head ache just skimming through this. I struggled with this concept when I first starting learning about map and compass. Once you get it, it is actually not that complicated. But the explanations for how it works, at least the numerous ones I have come across, make the topic thoroughly confusing. Visual aids, like the one by TrailBoss, make this a far easier concept to understand than written ones IMO. There is too much gobble-dee-**** in most of these explanations. Less is more. The orange idea mentioned earlier is not bad either.
Or you can buy a compass with declination adjustment, set it properly, and fuhgeddaboudit.
^^^ This. ^^^
Just remember to reset it appropriately when you travel to an area with a different declination.
Yikes. I have a popsicle head ache just skimming through this. I struggled with this concept when I first starting learning about map and compass. Once you get it, it is actually not that complicated. But the explanations for how it works, at least the numerous ones I have come across, make the topic thoroughly confusing. Visual aids, like the one by TrailBoss, make this a far easier concept to understand than written ones IMO. There is too much gobble-dee-**** in most of these explanations. Less is more. The orange idea mentioned earlier is not bad either.
So Here is less:
You only have to know this: On the map you measure in True, but the compass in your hand measures in mag. Just look at the declination diagram. Which angle is larger to your target, from mag N or from true N? When converting from one to the other, keep that in mind. That knowledge will tell you whether to add or subtract. It is as simple as that.
It's all about the declination diagram. You want to turn the screw adjustment on the compass so that the compass resembles the declination diagram. If you have done it correctly, the orienteering arrow on the bottom of the dial will point in the same direction as magnetic north on the diagram (to the left of the zero mark here in the eastern U.S.)Absolutely.......that is, once you find a comprehendable explanation of how to do this on one's compass.
When I showed this video to a friend a few weeks ago, the first question he had was related to declination. He wanted a slightly fuller explanation than "Do it this way because I said so." So yeah, I will add a little bit of content. Of course, I'm not trying to speak to the person who is super curious and just can't wait to dig into the specifics. There are quite a few sources online for detailed information. I'm going for the casual hiker who knows s/he's supposed to bring a compass and is dilligent enough to do so, but isn't quite sure what it's for. Our mantra throughout production has been, "How can we explain that concept in 1-2 sentences?" So that is what I am going for regarding declination. It will be something like, "The true north pole (that is, what your map points to) is different from the magnetic north pole (what your compass points to). To account for this difference when navigating by compass, we need to add a fudge factor to our bearing, and the fudge factor changes depending on where you are in the world. In the Appalachian Mountains, land of the AMC, we Add when going from Map to Compass. West of the Mississippi and elsewhere in the world, the rules are different, and the reasons why can be found elsewhere on the internets." Hopefully I can have a simple graphic of the earth, the locations of true and magnetic north, and lines of magnetic flux or whatever it's called.
Many people I know and respect as navigators adjust their compasses to account for declination in advance, in order to avoid having to add or subtract or whatever. I've found this process to be confusing, and for me personally, I tend to hike in a lot of different locations, ME, MA, NH, MT, WA state, CA, AK. And I just find it easier to remember to Add when going from Map to Compass in AMC land. And then the proper operation is obvious for everywhere else or for going compass to map.
I'd like to add a section on 'checking your work.' This amounts to comparing the bearing you're using on your compass to what you should expect based on what direction you want to go on the map. For example, going from Mt. Lafayette to Greenleaf hut is almost due west, which is 270 degrees (285 if you've included declination). If, after taking your bearing by putting your compass to map, your compass is very far off from 285 degrees, you've done something wrong. The most common mistake I see is for folks to align their compass dials anti-parallel to the N/S lines on the map, so they end up being 180 degrees off. So instead of going due west they go due east. This very bad, and is easily avoided by checking your work.
In a similar vein, one can simply estimate what direction they want to go in (say, northeast) by looking at their map. Then turn the compass to the appropriate value for northeast (45 degrees), add declination, and put red in the shed. And then they'll be walking northeast. It's a very quick and dirty way to know precisely what direction is what. "Hey, we're supposed to be going south, but south is THAT way. Maybe we're going in the wrong direction?" Or, "Geez, visibility really went to crap in a hurry, I don't know where the trail is. But I know the highway is straight west, so let's start walking on a bearing of 285 degrees, and we'll get there eventually." I feel like these simple steps would prevent a few rescues every year.
Raven, thanks also for your detailed pointers, I'll be adjusting the list of 10 essentials and giving my editor/producer (Eliza) a firm tongue-lashing. Who thinks sunblock is a 10 essential?! And yes, this needs to be pretty well second nature before you pull it out on Monroe with 50 mph winds and zero visibility. I wonder if I could put some 'homework' at the end to reinforce the concepts?
All, again, thanks for the enthusiastic feedback. SUPER useful.
When I showed this video to a friend a few weeks ago, the first question he had was related to declination. He wanted a slightly fuller explanation than "Do it this way because I said so." So yeah, I will add a little bit of content. Of course, I'm not trying to speak to the person who is super curious and just can't wait to dig into the specifics. There are quite a few sources online for detailed information. I'm going for the casual hiker who knows s/he's supposed to bring a compass and is dilligent enough to do so, but isn't quite sure what it's for. Our mantra throughout production has been, "How can we explain that concept in 1-2 sentences?" So that is what I am going for regarding declination.
The orange and nail idea is fine for novices,
Learn what the declination diagram tells you and you don't need any silly easily misunderstood mnemonics.DRAW PARALLEL LINES ON THE MAP AT HOME POINTING TO MAGNETIC NORTH.
Then the newbie only has to be taught to line up the parallel lines in the dial with the parallel lines on the map, while keeping the orienting arrow pointing toward the upper end of one of these lines.
This gets the job done, it minimizes mistakes, and it can be used all over the world.
The bulk of this thread confirms what I wanted to shout at 3 minutes into the video:
FUHGEDDABOUD TEACHING THE INTRICACIES OF DECLINATION!
Instead, teach your newbie audience to do what is done on competitive orienteering maps, and by people with other things to do than remember the various mnemonics that have been handed down through the ages, or the location of isogonic lines in North America or colorful diagrams:
DRAW PARALLEL LINES ON THE MAP AT HOME POINTING TO MAGNETIC NORTH.
Then the newbie only has to be taught to line up the parallel lines in the dial with the parallel lines on the map, while keeping the orienting arrow pointing toward the upper end of one of these lines.
This gets the job done, it minimizes mistakes, and it can be used all over the world.
[/rant]
Oh, and BTW: VFTT Pathfinders Group dedicated to this purpose
1) One must be aware enough to question that which may seem to be wrong. If it doesn't feel right, it probably is not. Does the trail I am on (since the last junction) seem to be going the right way? Do I even know the approximate compass direction I want to travel? Am I headed northeast when I should be going northwest (or worse)? Or is this no more than a temporary curve in the trail? Am I supposed to be following a stream? Am I supposed to be climbing and crossing over a ridge? If not, then examine what you have last done in the past tens of minutes to get where you are now. Compare to the map, develop a sense of terrain observation.The scenarios I'm looking to prevent are: 1) Walking down the wrong trail in the wrong direction for an extended period of time; and 2) Getting slightly off trail and having no idea whatsoever how to get back to safety.
Humans do not appear to have an innate sense of direction like many species of animals do. But subtle clues that you pick up along the way can help, Wind, sun, general slope of terrain and other factors can be learned (consciously or not) and applied practically naturally without even thinking much about it. You might be interested in watching this Youtube video. I show it to open my Land Nav training courses:I rarely get lost and my sense of direction is fantastic.
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