UKC

I'm a little traditional with my navigating, map and compass every time. There are however some hiking and climbing trips I've done where the remoteness, darkness and fog have made the navigating somewhat harder.
I've got an beat up old Garmin Etrex I use for simply getting a grid ref to take the guess work out of it on those wet, dark, late ones when the conditions have got really bad and I don't want to mess about. I don't use the Garmin as a navigator, use a 'where the hell am I?' button. My Garmin's compass isn't working right and I'm going to need a new unit.

TLDR:
All I want is an electronic tool that will simply give me a UK OS ref and nothing else. Does such a tool exist.

In reply to olddirtydoggy:
Have you got a smart phone? Plenty of apps to choose from.

In reply to olddirtydoggy:

The compass on the Garmin doesn't need to be working for it to give you a grid reference.

In reply to olddirtydoggy:

I have an etrex unit for sale. make me a sensible offer if interested.

In reply to olddirtydoggy:

Thanks for the replies.
First off I hate my Garmin, it's a house brick and fiddly. I don't have a smart phone either. Surely theres somebody making a simple hit button for grid ref. I popped into Go outdoors and the guy there said its the number 1 thing he got asked there but as far as he knew there wasn't anything. Decathalon used to do something but it didn't give UK OS refs.

In reply to olddirtydoggy:

Just buy an old iPhone 4s and turn everything off but GPS ?

Or get your soldering iron out and get yourself onto dragons den !

In reply to Dark-Cloud:

Seems about right, Though why you'd want an iphone rather than a cheap android phone I dont know....

There's probably a lot of manufacturers self interest at play here. There's no reason why the cheapest gps watch can't display a 6 fig grid ref, but that would hit the Suunto Ambit/Garmin XT680 ( or whatever model they're up to) market. Likewise why sell someone a grid ref only gadget when you can flog them an etrex?

In reply to Ridge:

Well iPhone, Android, Windows, whatever takes you fancy......

I thought some of the dedicated geocache GPS might offer just grid but they appear to be mapping too.

In reply to olddirtydoggy:

On a smart phone get the OS Locate app. It uses no power unless you switch it on. From switching on the GPS to getting a grid reference takes about 30 seconds. You only get a GR but once you have that and can use a map you know where you are!

In reply to olddirtydoggy:

I use The Gridpoint GB app on my iPhone. Works really well.

Andy

In reply to oggi:


That's the one I've used and found it pretty good.

In reply to Andrew Wilson:
That was my favourite as so simple. Problem is it does not work now with the latest os sadly.
My number 2 is GPS2Grid as it is also simple and allows connection to maps if required. No 3 is OS locate.

Appreciate that OP does not have a smartphone.

In reply to olddirtydoggy:

Thanks again for the help guys. It seems getting my hands on an old smart phone might be the way forwards. Talking to the bloke at Go, we made a similar conclusion as has been posted here. A simple watch sized 'where the hell am I?' button would wipe out a lot of sales for those fancy, over spec'd toys.

In reply to Dark-Cloud:

Android: 'Grid Reference'

'GPS Status' is also useful.

In reply to olddirtydoggy:


Why are you replacing the Garmin?

In reply to olddirtydoggy:

Have you seen the newish (since 2011) yellow Etrex 10 the replacement for the "old" bigger Etrex?...price from Amazon themselves varies some weeks but usually £72 to £81& -20C capability now (old one was -10 & I have seen them freeze). Also has GLONASS tracking so faster & will accept all types of AA batteries also now.

I like you, never owned a GPS, sold them, but prefer 1;25K maps & mirror compass & paying attention & only had a couple of bad errors in total white out, dark winter Scottish conditions over the past 20yrs, so not bad. However like you a "where the hell am I " quick button is a good idea, BUT in reality you also need to be able to navigate in the above conditions so require pre-programmed waypoints or route stored on GPS to follow. For the past 14yrs you have been able to get actual GPS position on moving map using Memory Map etc, & similar on Garmin, Magellan etc. But there have been flaws in the set-ups in my view, until now!

I prefer OS 1;25K mapping, paid £80 & got the WHOLE of North Scotland (North of Blair Atholl) also includes full UK OS road atlas (all maps zoomable & printable) from Memory Map, license to 5 devices, so have it on my iPad Mini which has cellular & therefore a built in GPS (cellular sim card not needed to work). Very good tracking & great to see on map & can do routing etc., but bulky & 0C temp lowest but use for other trips/car use . So have the Maps also on desktop & mark waypoints & routes on the desktop & copy via USB cable to Etrex 10 the ones for that day.

Simples!

In reply to Snowdave:

A GPS to confirm where you are can be an assistance to 'manual' navigation with map and compass; it just tells you where you are. Thereafter, you navigate as you would just a you would without the GPS. You don't need waypoints and routes.

One problem with the quick 'where the hell am I' is that it may not be quick; if you turn the GPS receiver on to get a position, it can take minutes to get a fix from a 'cold start'. So it's best to either leave it on, or turn it on the get a fix every couple of hours (thus refreshing the ephemeris data). A smart phone with network access may be able to bypass this cold start, by getting ephemeris data from the network (AGPS).

The other issue in mountains is shadowing and reflection, which can cause position errors up to hundreds of metres. Like all navigation tools, you need to keep your wits about you, and always question discrepancies. GNSS is not perfect and infallible...

In reply to captain paranoia:


Cairngorm plateau in full winter blizzard & gusting over 50mph, ski mountaineering in a ping pong ball, wind is blowing you on a parallel heading & you look at compass & you are going in correct direction, but have no visual clues to triangulate for correction, so you end up in a very dangerous position about 1 mile off course! GPS with pre-loaded waypoints would have made me not be in dangerous situation & would have been less stressful for all involved.


Just leave the GPS on in auto track mode & shove in rucsac, get out when you need it, no cold start & route logged so backtrack feature can be immediately used. NEVER rely on getting a mobile signal, huge parts of Scotlands mountains DO NOT have any mobile signal!


GLONASS is the Russia gps system, so the GPS can use BOTH the USA & Russia GPS satellites so it can see MORE at any one time, therefore the error rate is lower.

In reply to olddirtydoggy:

To answer a couple of questions. I hate my old Garmin and want to replace it because it's weight I don't need. The old software and general way it works is extremely hard to understand and half the problem is I can't be bothered to learn something I don't really need or want. All I want is a location, not a navigator, tracker or data as I can do that myself.

The unit does have bad moments. A couple of winters back in the Polish Tatra's it was throwing my location all over the place at the bottom of a huge buttress, it was useless.

Isn't it all a bit like kit now, a lot of clutter and noise. For me it's always been about the outdoors and climbing, the gadgets I don't care for unless they will make life much easier.

In reply to olddirtydoggy:

With similar requirements I bought a Garmin Foretrex 301. For last 4-5 years it has been turned on occasionally to help me locate myself. It is quick to locate (even if not used in some time or moved significantly e.g Wales to Scotland), very small and light, usable and displays a grid ref with 2 clicks of turn on. It was the closest, simplest tool I could find to just displaying a grid ref. It uses AAA batteries which I have tried to standardise on with my head torch etc.

In reply to olddirtydoggy:



Like I said previously the new (since 2011) version called the Etrex 10 is lighter, smaller, similar (slightly shorter) size screen, quicker & more accurate, & easier to use. Most GPS units have even basic tracking/waypoints etc even your old Etrex has them, just the newer ones have better user interfaces & are faster.


Get one that has GLONASS then like the Etrex 10, 20, 30 etc, & not the Forerunner, in fact most of the watch style ones only get GLONASS if you spend over £200, the Etrex 10 is £80 & has it!


Just did a nice cold start on my Etrex 10 GPS & running in GPS (not GLONASS) mode by pressing one button (only to turn on as it displays OS grid ref 10 digit on main first screen) it correctly showed my OS position whilst inside my house via three strong satellite signals within 40secs. Is that easy & fast enough for you?

Seriously go into a shop that has them in stock & take a look if not here is a link to Garmin spec page:-
https://buy.garmin.com/en-GB/GB/sports-recreation/hiking/etrex-10/prod87768...

In reply to Snowdave:


Oh, I agree wholeheartedly. The point I was trying to make was to counter your implication that using a GPS requires you to have a pre-planned route; it doesn't, if you don't want to.

If you want to use a pre-planned route, then, yes, it can certainly make life easier...


As I said: "So it's best to either leave it on...".


Agreed. Not that I suggested relying on a mobile network...

"A smart phone with network access may be able to bypass this cold start"

<emphasis added>


If it can receive GPS and GLONASS, it's a GNSS receiver...

Regardless of how many satellites it can see (or how many reflections...) my point still holds: don't trust it implicitly. Always question discrepancies.

In reply to olddirtydoggy:


Good example of shadowing and reflection causing position errors; large cliff faces create strong reflections, that extend the apparent line of sight path to the satellite, thus throwing the triangulation calculations off. The error jumps about as the constellation moves, and the reflections change.

In reply to captain paranoia:


& it's also WAAS/EGNOS, ....personally I just call it a "magic box of tricks".....hehe


It has batteries & a silicon chip, first rule of "don't trust it", but ever tried using a compass on the Isle of Rhum? Magnetic rock so it points to the nearest biggest bolder...great fun!

These newer Etrex GPS devices are soo cheap, robust, lightweight & accurate (it clearly states current error in ft or M on main screen), I think it is silly not to have one as a back up as they are better than anything else unless you want to spend ££££. However you do require some brain cells to use one & those same brain cells to relate your remaining visual surroundings to a map & compass which you should have as primary nav aids.

In reply to Snowdave:


I'm guessing this is a hypothetical? In that situation I'd either use GPS, or (because sods law, it would have been fully charged, with all the waypoints loaded, then just totally died for no reason) done that thing where one of you staggers/skis/plods/crawls to the limit of vision, the other one of you then waves your arms around until they're on the right bearing, then you walk to where they are. Repeat. Can take a while if the limit of vision is 30cm!

That, and if you know that 1 mile *that* way is pretty dangerous, aim off a bit the *not so dangerous* way. If there weren't any non-dangerous ways the direction I was going, I'd probably go back the direction I came.

...And have practiced lots when it's really windy but visibility is good, or it's really snowy but not very windy, or in places where I know that there's no big cliffs to 'navigate' over.

Not so great on a plateau, but can sometimes usefully use slope angles and changes in steepness to navigate when you can't see anything. Fiddly obviously, but again, something worth knowing about for the day when your GPS doesn't work for whatever reason, and also fun to practice in non-impending-death-by-unexpected-cliff situations.

Just as you shouldn't rely on getting a mobile signal, you shouldn't be 100% reliant on your GPS working. You don't always get a mobile signal. Likewise (but so much less often that it tempts you into forgetting) you don't always get a GPS signal.

In reply to PM:


Not hypothetical, actually happened, weather forecast from met office & MWIS was way out even guides I spoke to back at CG carpark were stunned & it was 50mph constant & up to 80mph when it was forecast for 25mph & occasion 50 gusts.

I re-checked the map & 1/2 mile out we were out when we had difficult situation, I meant to say not 1 mile, main reason is that even standing still the wind was blowing us sideways, but you could not feel it as the snow was hard ice top coating so we were moving without moving if you see what I mean.. So you are off course before you know it. Walking you feel the sideways push of wind against your fixed legs, not so in this situation.

The area we were aiming for I had allowed error, & aimed down the middle, just we got well blown to one side.

As for the crawl in front etc , yep done that, also now (not at time) have a red rope thrown line also with weight on end gives you slope condition in white out. My GPS has loads of safe waypoints & can do point to point straight line in safety. I now have about 25 waypoints to cover the whole plateau & mtns including some off to the side.

In reply to Snowdave:

Yikes, sounds 'character-building'. Pesky climate change. : )

Throw line's an interesting idea; hadn't heard of that before.

In reply to Snowdave:


They only give corrections for GPS, not GLONASS.

And they're really only intended for use in benign multipath environments (think aircraft), since they only correct for clock and ionospheric errors. The system knows nothing about your local shadowing/multipath environment, so cannot and does not supply corrections for them.

In 'difficult' environments, multipath, shadowing and reflection dominate the errors.

In reply to Snowdave:

My apologies for banging on. It's a bit of a mission to try to ensure people understand the limitations of GNSS, and can thus use it appropriately...

In reply to Snowdave:


... How do you know the error value is accurate though? ; )

In reply to olddirtydoggy:

There's some great replies here. Thanks very much for all the info here, UKC delivers again.

In reply to captain paranoia:


I agree a handheld GPS & even a 1:25,000 map have limitations, & I find them thus...hehe

because I did surveying at Uni, & also used to work as a "trouble shooter" in the cartographic dept for the Hydro Board (Now SSE). We used OS base mapping at 1:1,250 scale (then scaled up or down as required) & I have used surveying instruments from basic manual dumpy levels to highly complex EDM systems. LOL!

The main instrument is a brain/MK1 eyeballs, that can observe & relate a 1;25,000 map to the landscape, most people fail at this & can only just handle a 1:50,000 which is no where near detailed enough for certain areas in the UK. Once you have learnt to do this then learn how to handle a good mirror compass, then a GPS as a back up.

To be realistic thought a GPS supplied OS 10 figure (excluding letters) grid ref is down to the last 1M, a 1;25,000 map at scale can be easily read down to 6 figure (100M) & if careful an 8 figure (10M), so a 10 figure ref is not really needed for said map. So any inaccuracies which a GPS states will usually affect a 10 or 8 figure grid ref.

GLONASS just makes the number of satellites that the GPS unit can talk too higher, so a better chance of physically "seeing" (line of sight) more for better accuracy & faster position fix.

In fact in the instructions under waypoints it does state that if you want really accurate waypoint (ie you want to log an actual waypoint out in the field) then leave in place/position for about 90 mins. That might sound silly, but for such a small unit this is a good way for it to repeatedly talk to the satellites & bring the accuracy right down to the 1M!

However when using bigger commercial pro units to survey a field say, you have a big antenna backpack style & hand unit to move around with & then a stand alone base station in one static place in field with it's own antenna & then the two units talk to each other & compare the readings between the two.

In reply to PM:


The dangerous situation which I'm leaving the details out was VERY character building & about 4yrs ago, thankfully managed to get ourselves out of it (my attitude is you SHOULD be able to get yourself out of situations with gear & brains), no MRT called or needed (last resort), new underwear required LOL, but shock set in badly with an other member which then lead to the start of hypothermia, thankfully this was when we had got to the ski runs at CG, person was ok though after a hot drink in the base station!!


Yes it's in a Ski-MTN book I have, I have about 7-10M of red Beal EN climbing cord size 7 or 8mm dia. Each end is fig 8 loop with DMM red snapgate krab, & other alpine butterfly knots on rope to form basic waist belt. Can also be used as emergency "catch-line" as strong enough. So dual purpose as 7 -10M is about as much as you can throw in straight line with moderate wind. Krab weights end, & red line highly visible in snow so gives slope tell tales, saves using other items & making snowballs. stores in very small stuff sac.

In reply to PM:


You don't. And neither does the receiver. It's just an estimate, calculated in some unspecified and probably proprietary way*, based on a statistical analysis of the received signals.

These error values don't seem to account for reflection errors...

* happy to be put right if someone can point me to any manufacturer's description of how these readings are calculated...

In reply to Snowdave:


Listen to, of course...

In reply to Snowdave:

They are accurate, HOWEVER you've made a classic error regarding accuracy and precision. An anology: you shoot three arrows at a target. The closer to the middle they are, the more accurate. The closer to each other they are, the more precise. Hence it is possible to be accurate and precise, inaccurate and precise, and inaccurate an imprecise (the fouth combination is generally difficult to acheive). The +/- error reported by the GPS is the precision - i.e. the circle within which each GPS ping (they update at second to sub-second resolution) is, in the above analogy, the closeness of the arrows. The unit cannot quantify the accuracy as you do not know your exact location, so no comparision can be made. As such a +/- error of 3m means the unit can estimate your location to within 3m - this may be a long way from where you actually are.

Rant over.

In reply to captain paranoia:




The "error" values report the degree of precision of the location calculated by the unit, and have nothing to do with how accurate it is. Given that not all signals will be reflected, this estimated precision value will increase when experiencing multipath errors (reflectance) as the travel time of signals between the unit and satellite has a greater variation; variation between non-reflected wave travel times will be sub-millisecond, whereas reflected wave travel times will differ from non-reflected wave travel times in the order of milliseconds. This results in a bigger radius of calculated positions, and hence a lower degree of precision, translating into a greater +/- error.

In reply to ianstevens:



Pedantic you are, I'll re-print a section from one of my posts above

""To be realistic though a GPS supplied OS 10 figure (excluding letters) grid ref is down to the last 1M, a 1;25,000 map at scale can be easily read down to 6 figure (100M) & if careful an 8 figure (10M), so a 10 figure ref is not really needed for said map. So any inaccuracies which a GPS states will usually affect a 10 or 8 figure grid ref.""

If I want GPS readings more accurate than what I can easily see on a map I'll borrow a Pro two unit job, but that's useless for general mountaineering which is what we are talking about here.

In reply to Snowdave:


If using terminology correctly makes me a pedant, than its a label I'm happy to accept. Words have definitions for a reason, and as such we should aim to use them appropriately.



Agreed on all counts here.

In reply to ianstevens:


I'm familiar with DOP.

But Snowdave said:


So, apparently not reporting DOP, but reporting error radius(?), which is the point I was addressing.

To go back to DOP: are you sure you know how a given receiver is calculating DOP...? Without access to the source code, I certainly don't. DOP is also a bit esoteric for the average user, so is probably why Garmin have added an error radius.