Poster: A snowHead
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I'm pondering buying an altimeter or altimeter \ watch combo.
Any suggestions ? I don't usually wear a watch, but messing about with a phone in a blizzard isn't ideal.
On the subject of phones, my fancy mobile has a GPS altimeter function, but when compared with an OS map there seems to be quite an error - up to 100m vertical, despite the display noting an accuracy of +/- 2 or 3 meters.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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david@mediacopy, I've a Nike one which I bought new from an ebay seller a few years ago. It's alright as a a bit of a toy but as it works on barometric pressure if you are after accuracy I wouldn't think it's anywhere near as accurate as GPS.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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You need to Login to know who's really who.
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david@mediacopy, Suunto Observer, I wear it everyday as a normal watch.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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I used a Suunto Core when I did the Mountain Safety course. Found it very useful as a navigation aid. AIUI GPS is not especially good for altitude, but if you calibrate a device based on barometric pressure to a known altitude at least once per day it should be much more accurate.
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You'll need to Register first of course.
You'll need to Register first of course.
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I've got a Suunto Core as well.
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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Cheers Guys, I'll check those out.
Mike Pow, That looks pretty useful. I can't see any UK dealers on the web - do you know of any ?
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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the chavy sportsdirect.com sell suuntos online, some at very good prices
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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the suunto is really useful for an altimeter but the other "features" are kinda pointless... the compass is rubbish as it is in constant need of recalibrating so not reliable, the thermometer is stupid as it just tells you your body temp and takes ages to cold soak should you take it off to check actual temp.
but i wear it everyday and it is bullet proof
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You know it makes sense.
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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^^^ i attach my watch to one of the straps on my pack
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Poster: A snowHead
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I've got a Swatch Snowpass (compatible with lots of ski passes in Europe) which also has a fairly good altimeter on it. Cheap, cheerful, looks cool...
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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You need to Login to know who's really who.
You need to Login to know who's really who.
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I would be wary of thinking that a barometric altimeter is going to be 'accurate' for a couple of days - that requires pretty stable weather conditions. In changing conditions, I would not rely on one for more than an hour, if that; as an example, I climbed Ben Nevis a few years ago on a not too nice May day - as I was happy with my other navigation skills, I stopped recalibrating my altimeter after a while, only to find that it had me descending all the rest of the way up; clearly there was a weather front coming in, but I would not have wanted to be relying on it for very long after each time I recalibrated.
Conversely, I have a bottom of the range (and 10 year old) Garmin Etrex; this is a model without barometric altimeter, because I felt that an accurate grid reference should generally be enough and I didn't want anything else draining the battery of what is just an emergency tool. Looking at that on numerous high and low level walks, however, I have found that the altitude readings given have been pretty good - generally within 10m or so of what the map says.
If you are after a GPS which will give decent altitude readings, get a 'proper' one, rather than using a mobile 'phone - perhaps those made for mountain navigation have a little more work put into the altitude part, I don't know.
I have often read on mountaineering forums and in magazines that the altitude reading on a GPS is not reliable, but I would be just as happy to use one (I presume you are looking to keep track of daily ascent/descent rather than for whiteout navigation?) as I wold be to use a barometric one. In the end, you just need to accept and understand the limitations of whichever you choose.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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parlor,
OP said
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altimeter or altimeter \ watch combo. |
this is clearly a catagory 1 option.
Yellow Pyranha,
Altitude can only be measured by a barographic instrument, by definition.
Height on the other hand can be measured by survey techniques etc. GPS would give a good approximation of height.
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You'll need to Register first of course.
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Not a semantic distinction that I've ever come across. Where does 'elevation' fit in your definitions?
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All altimeters, as opposed to GPS devices, work on Barometric pressure. I use one with a map and compass. I will reset the pressure setting whenevert I am at a known height (e.g. sitting in a mountain hut). After a few hours, it will usually be a few m out compared to a map, but still accurate enough to help me work out where I am, traverse in fog without loosing height etc..
GPS heights work of relating position to map height... this is not the same thing at all.
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ski wrote: |
GPS heights work of relating position to map height... this is not the same thing at all. |
Is that the case with all instruments? If you can "see" 4 GPS satellites you can derive a 3d fix. If you can see 3, you can only be at one of two points, one of which will usually be deeply implausible.
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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Quote: |
Is that the case with all instruments? If you can "see" 4 GPS satellites you can derive a 3d fix. If you can see 3, you can only be at one of two points, one of which will usually be deeply implausible.
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You end up with a Lat/Long (position) - which then gets interpreted into a height. GPS does not measure elevation.
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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Did a few searchs.. I stand corrected. Will stick with a barometric altimeter tho
Last edited by snowHeads are a friendly bunch. on Mon 1-11-10 12:03; edited 1 time in total
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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ski wrote: |
Quote: |
Is that the case with all instruments? If you can "see" 4 GPS satellites you can derive a 3d fix. If you can see 3, you can only be at one of two points, one of which will usually be deeply implausible.
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You end up with a Lat/Long (position) - which then gets interpreted into a height. GPS does not measure elevation. |
It gives a point in three-dimensional space, from which, given some model of the earth - NOT including detailed topography - it can give lat, long and elevation. Some, maybe most, receivers, might assume (or be configured thus) that you are bound to the surface of the earth and look up on a map before deciding on what it's going to tell you for your elevation. I'm sceptical of that, but maybe you can show me otherwise. My main point is that GPS is capable of fixing you in three-dimensional space.
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You know it makes sense.
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david@mediacopy,
As suggested by Spyderman, rob@rar and Mosha Marc, the Suunto range of watches has a great reputation for the requirement.
Quite widely used in the military as well...
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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laundryman,
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My main point is that GPS is capable of fixing you in three-dimensional space
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But is it as accurate as a properly set barometric altimeter ?
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Poster: A snowHead
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ski, potentially - mind you, the guy may have been using a rather nifty GPS. Even so, I was surprised at the accuracy.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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I've often read that GPSs are poor at calculating altitude. My experience of using one for nearly ten years is contrary. In practice, with a clear view of the sky, mine concurs with OS spot heights to within ten metres. Only once have I noticed a wild discrepancy when, on the summit of Kebnekaise, it was under reading by perhaps 100m. I later realised that it was still set for UK coordinates and, because of the elipsoid nature of the earth, the MSL would be different.
As I see it the advantages for each are as follows:
Barometric Altimeter
* Low power requirement
* Can be very accurate
* Consistent under tree cover and in canyons
GPS
* Not reliant on recalibration
* Not reliant on accuracy of maps/guardians for recalibration
* Generally consistent
* Gives position too
Some GPS units include a barometer and electronic compass too e.g. the Garmin Foretrex 401 pictured above. The obvious answer is to know the limitations of your tool!
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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ski wrote: |
laundryman,
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My main point is that GPS is capable of fixing you in three-dimensional space
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But is it as accurate as a properly set barometric altimeter ? |
Sorry, my previous post crossed with your retraction. I've not used a GPS for elevation (only for yachting, where it shouldn't be an issue!) so I can't give a good answer. I do know that on a bike with a barometric device, I can calibrate it at sea level at the start of the day, and when I get back to sea level a few hours later it can be +/- 50' out.
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You need to Login to know who's really who.
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altis, laundryman, Thanks... I've learned something
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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You'll need to Register first of course.
You'll need to Register first of course.
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Axsman, or Journey to the Centre of the Earth.
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I have found the Nike watches to be the best over the years. More accurate altimeter and much easier to use than Suunto - I know, not what you'd think but simply true (against Observer and Core). Compass on Observer is better except on Core which is prone to sticking. The Tissot Touch is better than all but expensive. The EMS Highgear Axio looks a great price and I will pick one up in December in NYC for a test.
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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Hi all,
I went Suunto Core in the end. Seems reasonable on the local hill, and as expected needs resetting regularly in changeable weather.
I also found some different GPS software ("GPS Test") for my phone and that's a lot better, and confirms the watch to within a few meters. The only issue is that it takes a few minutes to sync.
The Suunto is my first watch since childhood so it will be interesting to see how long it lasts before I break it
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