Author Topic: Magnetic compass on Viewranger behaving strangely  (Read 2774 times)

Rob Goes Walking

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Re: Magnetic compass on Viewranger behaving strangely
« Reply #60 on: 16:55:14, 16/04/19 »
https://getoutside.ordnancesurvey.co.uk/guides/top-tips-for-map-reading/

Thanks. This seems useful but I don't understand it:

https://getoutside.ordnancesurvey.co.uk/guides/advanced-contours-and-relief/

Section "Using contour lines for navigation"

I don't understand about "direction the slope is facing".  I expect it's in the book I ordered and I'll have a look for a video but if anyone knows of a video demonstrating reading slope aspect that would be handy.

Also, what's a back bearing?

richardh1905

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Re: Magnetic compass on Viewranger behaving strangely
« Reply #61 on: 17:32:57, 16/04/19 »
Thanks. This seems useful but I don't understand it:

https://getoutside.ordnancesurvey.co.uk/guides/advanced-contours-and-relief/

Section "Using contour lines for navigation"

I don't understand about "direction the slope is facing".  I expect it's in the book I ordered and I'll have a look for a video but if anyone knows of a video demonstrating reading slope aspect that would be handy.

Also, what's a back bearing?



I had a read of the link, possibly a useful technique if you are lost. Direction that the slope is dropping or descending would be a better choice of words, perhaps. Just face downhill. I've never had to do this.

Owen

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Re: Magnetic compass on Viewranger behaving strangely
« Reply #62 on: 17:43:45, 16/04/19 »
Stand on the slope and face directly downhill, that's the direction the slope is facing. If you take a bearing of the direction you're facing you can use that to find your location as long as it's not a long straight hill.
As long as you're on a rounded hillside if you find the point where your bearing matches the slope on the contour lines you are somewhere on that line.
A back bearing is the reverse of a bearing i.e the bearing of where you've just come from. Easiest way to find it is to read it off the back of the compass. Opposite where you normally read the bearing. You should adjust it for magnetic north but as the difference at the moment is so small it's not worth bothering about.

Owen

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Re: Magnetic compass on Viewranger behaving strangely
« Reply #63 on: 17:50:32, 16/04/19 »

 I've never had to do this.


It's more of a skiers thing, because we zigzag about so much it's easy to loose track of whereabouts you are on a slope.

Rob Goes Walking

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Re: Magnetic compass on Viewranger behaving strangely
« Reply #64 on: 17:53:00, 16/04/19 »

I had a read of the link, possibly a useful technique if you are lost. Direction that the slope is dropping or descending would be a better choice of words, perhaps. Just face downhill. I've never had to do this.

Thanks. I liked the idea of being able to precisely locate yourself using nothing but the contour lines but if it's really more for skiers I guess I'll wait and see how my other skills go before practicing it.

Rob Goes Walking

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Re: Magnetic compass on Viewranger behaving strangely
« Reply #65 on: 17:55:00, 16/04/19 »
Thanks Owen that makes sense.

Owen

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Re: Magnetic compass on Viewranger behaving strangely
« Reply #66 on: 18:27:33, 16/04/19 »
Don't dismiss it it's a handy technic to know.

Skip

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Re: Magnetic compass on Viewranger behaving strangely
« Reply #67 on: 14:49:59, 17/04/19 »
Don't dismiss it it's a handy technic to know.
Absolutely agree - slope aspect can be an important aid to locating a position.More generally, interpreting contours is a fundamental skill.


@ Rob (and anyone else who wants to learn the basics of nav). There is a wealth of online training information about navigation available free of charge.

Start with the Mountaineering Council of Scotland
https://www.mountaineering.scot/safety-and-skills/essential-skills/navigation


Then study the well-known 'Navigators Dozen' from WalkHighlands
https://www.walkhighlands.co.uk/safety/navigators-dozen.shtml


Or the dozen in simplified DofE format
http://www.meadowsdofe.org.uk/wp-content/uploads/2015/04/navigators-dozen.pdf


IMO, if you study, practice and master the 'Navigators Dozen', you will be able to effectively navigate in Britain's Hills.


Finally, here is specific instruction on using a compass from The Ramblers
https://www.ramblers.org.uk/advice/navigation/using-a-compass.aspx?gclid=EAIaIQobChMIjfqwxaDX4QIVkhrTCh1OiQqmEAAYAiAAEgIVzvD_BwE
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Rob Goes Walking

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Re: Magnetic compass on Viewranger behaving strangely
« Reply #68 on: 15:01:49, 17/04/19 »
Absolutely agree - slope aspect can be an important aid to locating a position.More generally, interpreting contours is a fundamental skill.

I was hoping I'd learn to visualise contours by practicing nav skills, I mean I know what they are and the obvious such as closer together they are the steeper it is and a few of the features they form but I still would like to better "see the hill" without having to resort to a 3D fly through in ViewRanger.

My compass, nav book, waterproof pen and waterproof notebook are all waiting at the post office for me to pick them up. In fact I'll go do that and print off some smaller maps at the library.

Thanks for the links skip.

Skip

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Re: Magnetic compass on Viewranger behaving strangely
« Reply #69 on: 16:08:37, 17/04/19 »
I was hoping I'd learn to visualise contours by practicing nav skills ...
That is exactly how you will learn, Rob. 'Practice' is the key word there. Go out to a known point, set your map (see below) then look at the landscape in front of you and relate it to the contours on the map.

I'd be the first to concede it's not the easiest skill to master (in fact, I still find it takes concentration) but it's well worth it.

PS this may be helpful: "Setting the map is the technique of positioning the map so that all the features are lined up with your own location as the central point. What is in front of you on the ground will be in front of you on the map, what is to your left on the ground will also be to your left on the map and so on. The writing on the map may be upside down or sideways but this is OK - having the map set is far more useful in relating the map to the ground than being able to read the writing."
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Rob Goes Walking

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Re: Magnetic compass on Viewranger behaving strangely
« Reply #70 on: 14:18:55, 22/04/19 »
OK I'm trying to move this navigation chat out of the awning :)

After reading bits here there and everywhere I've decided to try to learn from the book I bought, the Ultimate Navigation Manual. I started reading it and it promises me that it will take me from newbie to expert if I read it in sequence teaching me something called micro navigation rather than orienteering. This may be sales puff but if it can do it I'm pleased. I think probably the book combined with the videos you have posted links to when the book gets to those sections may be the way to go.

But I have a question the book can't answer. The book says don't go somewhere unknown and practice these techniques but practice them somewhere known. I don't really know anywhere as I've made a point of visiting each location in Cumbria just once as there's just so much to explore. Is this advice about learning the techniques or safety? I'm guessing safety as navigation courses would take me somewhere unknown to practice. If it's safety I'll choose to bend this rule a bit as I have GPS that should be able to stop me getting lost (it's worked so far). But I wanted to confirm this.

Where did ninthace say was a good place to practice navigation? I can't find it in this thread (here's hoping the man himself reads this, he can regale me with today's tale teased about on the awning).

Thanks

Rob Goes Walking

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Re: Magnetic compass on Viewranger behaving strangely
« Reply #71 on: 14:39:04, 22/04/19 »
I think I can already see what fernman meant about not using most of this stuff, I don't need to predict wind speed from isobar there's a forecast for that and I doubt I'll need to work out directions from the prevailing wind but I'll persist with the book as it's easy to understand so far. There are probably better choices of book though.

ninthace

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Re: Magnetic compass on Viewranger behaving strangely
« Reply #72 on: 15:14:37, 22/04/19 »
So that's where you went.  I think the navex you refer too may have been this one http://www.haroldstreet.org.uk/routes/download/?walk=1646 which has a long leg on a compass bearing in fairly open country with the aim of hitting the Pennine Way at a specific point.


Now as to my tale of "derring do".  You will remember I advocated always having a map with you "just in case"?  Well this morning we parked the car next to a pub in a village not far from Exmoor with the intention of doing a 15 km circuit up on to the moor and back in time for beer o'clock and a bite of lunch.  All went well for the first 6km or so which involved a fair bit of up and down, the odd stream crossing and some fairly rough going, leavened I might say by spotting a herd of 20+ deer on the skyline on the way.  We had just got to some flatter stuff and upped the pace a bit when the calf problem I had had on the last walk reasserted itself with a vengeance.  Walking was painful but not impossible so we decided to cut the walk short. Needless to say this involved an abrupt departure from the prepared route loaded into VR and the Garmin.
Now here is the brief young Rob.  Work out a route from your current position avoiding rough country and steep gradients that will get you back to the car in the minimum time without damaging the affected limb any more than you have to.  And that my Padawan is why you carry a map and learn how to read it and extract every nuance from it. 
Solvitur Ambulando

Rob Goes Walking

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Re: Magnetic compass on Viewranger behaving strangely
« Reply #73 on: 16:23:32, 22/04/19 »
I've just got to the compass section of the nav book but I've had enough reading for now. I learnt a little bit about contours, and surprised myself by being better at visualising features than I realised. I haven't practiced terrain association though and I'm still not that great at visualising slope angle though though I get the gist of it. I'm also still a bit confused about slope aspect, this has now been explained to me in several different ways by different sources, I seem to remember almost getting it when Owen on here explained it, I'll have to dig through and find his description again. Learned a little about mapping systems but I already knew most of it. It's a good book so far though it started off with things I thought were pretty pointless like navigating by aircraft trails. I'll have to see how the compass section goes next.

Rob Goes Walking

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Re: Magnetic compass on Viewranger behaving strangely
« Reply #74 on: 16:44:54, 22/04/19 »
Your nav practice trace looks like it would take a while. I expect once I'm done reading this book I'll just take the map and compass with me on my normal walks and try to leave ViewRanger in my pocket, it will beep at me anyway if I lose track. This navigation practice is going to have an adverse effect on my trip times though, I'll have to select shorter routes.