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Has anyone used this yet?
It's a free app for iPhones etc, that gives a compass and six figure grid reference of your position when switched on. This now means that I won't have to take my old garmin house brick as location back up ever again
It's a free app for iPhones etc, that gives a compass and six figure grid reference of your position when switched on. This now means that I won't have to take my old garmin house brick as location back up ever again
In reply to Skol:
Should work anywhere - at least, there have been similar apps around for a few years that do.
Should work anywhere - at least, there have been similar apps around for a few years that do.
In reply to JamButty:
Quite!
Does it not offer anything more accurate than a 6 fig grid ref? I've already got an app on my Android that gives a 10 fig grid ref!
Quite!
Does it not offer anything more accurate than a 6 fig grid ref? I've already got an app on my Android that gives a 10 fig grid ref!
In reply to Welsh Kate:
It might give you 10 figures, but it's not accurate. A 10 figure ref implies accuracy to within 1 metre.
> Quite!
> Does it not offer anything more accurate than a 6 fig grid ref? I've already got an app on my Android that gives a 10 fig grid ref!
It might give you 10 figures, but it's not accurate. A 10 figure ref implies accuracy to within 1 metre.
In reply to Ridge:
I would hope it's more accurate than the 100m that a 6 fig grid ref can give; the GPS on my phone certainly is.
I would hope it's more accurate than the 100m that a 6 fig grid ref can give; the GPS on my phone certainly is.
In reply to Skol:
It works without any signal at all. (Don't ask how it does it - I've no clue.)
It does 'only' give a six figure reference but for me and I'd guess most people that does for most of my needs.
I have a gps which gives a eight or ten figure grid ref but given that it often says its +/- 10m doesn't make it any more valuable!!
It works without any signal at all. (Don't ask how it does it - I've no clue.)
It does 'only' give a six figure reference but for me and I'd guess most people that does for most of my needs.
I have a gps which gives a eight or ten figure grid ref but given that it often says its +/- 10m doesn't make it any more valuable!!
In reply to JamButty:
Yes. You know - along the hallway and up the stairs and all that. Didn't you do it in GCSE geography?
> 6 fig?????
Yes. You know - along the hallway and up the stairs and all that. Didn't you do it in GCSE geography?
In reply to Skol:
I haven't seen the App, so maybe its better than first impressions, but I would have thought OS would be more responsible and give a more accurate App, rather than encouraging people to rely on this when a 100m box on a mountain is a massive range.
I haven't seen the App, so maybe its better than first impressions, but I would have thought OS would be more responsible and give a more accurate App, rather than encouraging people to rely on this when a 100m box on a mountain is a massive range.
In reply to Dave Perry:
Assuming you mean 'no phone signal', then, since the iThings include a GNSS receiver, it works by receiving the GNSS signals. There's absolutely no reason why a GNSS receiver in a phone needs a phone signal. Some poorly-designed phones may insist on getting A-GPS information from the network, and refuse to allow the GNSS receiver to present a fix until A-GPS has been received, but that would be very poor software design, since the GNSS receiver will acquire the information from the constellation anyway (it will do a cold start, acquiring the almanac and ephemeris provided by A-GPS).
An alternative app that has been around for years, and works very well, is 'Grid Reference', which does what it says on the tin, and can be set to present 6, 8 or 10 figures. It would be nice if it gave an error radius, as a number of apps such as OruxMaps or Locus do, or a standalone GNSS receiver.
A receiver that displays a 10-figure GR is telling you the position of the centre of its error 'circle' (and it ought to present its error radius). This is notably different from the grid reference convention, which is to identify the bottom-left corner of the potential position (specifying the location as somewhere in the square above and right, size depending on the resolution of the GR). As such, as GNSS reading should be considered coordinates, not a grid reference...
> It works without any signal at all
Assuming you mean 'no phone signal', then, since the iThings include a GNSS receiver, it works by receiving the GNSS signals. There's absolutely no reason why a GNSS receiver in a phone needs a phone signal. Some poorly-designed phones may insist on getting A-GPS information from the network, and refuse to allow the GNSS receiver to present a fix until A-GPS has been received, but that would be very poor software design, since the GNSS receiver will acquire the information from the constellation anyway (it will do a cold start, acquiring the almanac and ephemeris provided by A-GPS).
An alternative app that has been around for years, and works very well, is 'Grid Reference', which does what it says on the tin, and can be set to present 6, 8 or 10 figures. It would be nice if it gave an error radius, as a number of apps such as OruxMaps or Locus do, or a standalone GNSS receiver.
A receiver that displays a 10-figure GR is telling you the position of the centre of its error 'circle' (and it ought to present its error radius). This is notably different from the grid reference convention, which is to identify the bottom-left corner of the potential position (specifying the location as somewhere in the square above and right, size depending on the resolution of the GR). As such, as GNSS reading should be considered coordinates, not a grid reference...
In reply to JamButty:
Accuracy of a GNSS receiver is really outside the control of the OS...
Whilst a decent, modern GNSS receiver equipped with SBAS ought to be able to give a fix with around 8m error, the accuracy of that reading may depend on local geomorphology; canyon effects, reflections, etc. can displace the reported position by 100s of metres, and these errors cannot be corrected by SBAS (WAAS, EGNOS), because SBAS knows nothing about the local environment.
If you use a GNSS, you need to understand that it can give incorrect readings, and you need to learn to understand why, and when you might need to question the position fix it gives. The 'accuracy' of a GNSS receiver, and its DOP and error estimates are very beguiling... Be vigilant.
> but I would have thought OS would be more responsible and give a more accurate App
Accuracy of a GNSS receiver is really outside the control of the OS...
Whilst a decent, modern GNSS receiver equipped with SBAS ought to be able to give a fix with around 8m error, the accuracy of that reading may depend on local geomorphology; canyon effects, reflections, etc. can displace the reported position by 100s of metres, and these errors cannot be corrected by SBAS (WAAS, EGNOS), because SBAS knows nothing about the local environment.
If you use a GNSS, you need to understand that it can give incorrect readings, and you need to learn to understand why, and when you might need to question the position fix it gives. The 'accuracy' of a GNSS receiver, and its DOP and error estimates are very beguiling... Be vigilant.
In reply to Ridge:
My experience of using grid refs (coordinates?) off mobile phones is that they're almost better than a 6 figure grid ref - generally seem accurate to within 10m (if not 1m), so 8 figure reference would almost certainly be more useful than 6 figure one.
> It might give you 10 figures, but it's not accurate. A 10 figure ref implies accuracy to within 1 metre.
My experience of using grid refs (coordinates?) off mobile phones is that they're almost better than a 6 figure grid ref - generally seem accurate to within 10m (if not 1m), so 8 figure reference would almost certainly be more useful than 6 figure one.
In reply to JamButty:
Fair enough. But whenever I've needed to use a Gps as a confidence boost, I've never paid any attention to anything but 6 figure references. This has been more than enough to locate myself in a 100m square. I think it's good value seen as it's free.
> I haven't seen the App, so maybe its better than first impressions, but I would have thought OS would be more responsible and give a more accurate App, rather than encouraging people to rely on this when a 100m box on a mountain is a massive range.
Fair enough. But whenever I've needed to use a Gps as a confidence boost, I've never paid any attention to anything but 6 figure references. This has been more than enough to locate myself in a 100m square. I think it's good value seen as it's free.
In reply to Skol:
I use OStoGrid. '12 figures' ie AB 12345 67890. Also if you have a signal you get satellite and map 'underlay'.
Seems pretty useful to me.
I use OStoGrid. '12 figures' ie AB 12345 67890. Also if you have a signal you get satellite and map 'underlay'.
Seems pretty useful to me.
Post edited at 18:46
In reply to JamButty:
It's intended to be used with a map, not on it's own, and 6 digits is perfectly adequate to narrow down where you are on a paper map.
It's intended to be used with a map, not on it's own, and 6 digits is perfectly adequate to narrow down where you are on a paper map.
In reply to JamButty:
I really, really don't think that OS are encouraging anybody to RELY on this app.
And to suggest that they are irresponsible for putting this 'inaccurate' app out there is a bit crass. A 6 fig grid reference is better than nowt.
But I forgot. You are judging without actually having seen it.
Sigh.
> I haven't seen the App, so maybe its better than first impressions, but I would have thought OS would be more responsible and give a more accurate App, rather than encouraging people to rely on this when a 100m box on a mountain is a massive range.
I really, really don't think that OS are encouraging anybody to RELY on this app.
And to suggest that they are irresponsible for putting this 'inaccurate' app out there is a bit crass. A 6 fig grid reference is better than nowt.
But I forgot. You are judging without actually having seen it.
Sigh.
In reply to CasWebb:
Exactly. I use map and compass and am not often misplaced. I don't need 8,10,or 12 figures to relocate if necessary in a 100m square. It's just nice to have that backup on a phone which I will carry anyway for times of low confidence.
We don't know were born nowadays.
> It's intended to be used with a map, not on it's own, and 6 digits is perfectly adequate to narrow down where you are on a paper map.
Exactly. I use map and compass and am not often misplaced. I don't need 8,10,or 12 figures to relocate if necessary in a 100m square. It's just nice to have that backup on a phone which I will carry anyway for times of low confidence.
We don't know were born nowadays.
In reply to Craigyboy13:
The americans no longer limit accuracy.
This post is interesting and suggests 3m accuracy for phones that can also use the Russian satelites
http://www.tristate-engineering.com/2/post/2013/03/mobile-phone-gps-accurac...
The free android app GPS Status gives you the accuracy estimate, I'm currently getting 9m indoors by the window. Unfortunately it doesn't convert to Nat Grid refs.
The americans no longer limit accuracy.
This post is interesting and suggests 3m accuracy for phones that can also use the Russian satelites
http://www.tristate-engineering.com/2/post/2013/03/mobile-phone-gps-accurac...
The free android app GPS Status gives you the accuracy estimate, I'm currently getting 9m indoors by the window. Unfortunately it doesn't convert to Nat Grid refs.
Post edited at 21:14
In reply to andyathome:
I'm going to sound a curmudgeonly old dinosaur with this next bit:
Are people really worried about getting hopelessly lost in that big, scary 100 metre square box?
> I really, really don't think that OS are encouraging anybody to RELY on this app.
> And to suggest that they are irresponsible for putting this 'inaccurate' app out there is a bit crass. A 6 fig grid reference is better than nowt.
I'm going to sound a curmudgeonly old dinosaur with this next bit:
Are people really worried about getting hopelessly lost in that big, scary 100 metre square box?
In reply to andyathome:
which I why I said its my first impression. Whilst it may not be OS's intention, the risk is more people will be attracted to using this as technology instead of maps. There's too many examples of people lost without maps now, and if they rely too much on a general grid ref it will get worse!!
> I really, really don't think that OS are encouraging anybody to RELY on this app.
> And to suggest that they are irresponsible for putting this 'inaccurate' app out there is a bit crass. A 6 fig grid reference is better than nowt.
> But I forgot. You are judging without actually having seen it.
> Sigh.
which I why I said its my first impression. Whilst it may not be OS's intention, the risk is more people will be attracted to using this as technology instead of maps. There's too many examples of people lost without maps now, and if they rely too much on a general grid ref it will get worse!!
In reply to Skol:
Though your garmin is probably waterproof, fairly shockproof, and has a much longer battery life than the phone. The app is better than nothing (especially as it is free and weightless if you already carry the phone), the garmin is probably better than the phone. Of course it's fine to use either (or neither), everyone makes their own choices about the amount of kit to carry, but I personally treat GPS as emergency kit and like my emergency kit to be robust.
Also, some things captain paranoia said bear repeating for the benefit of readers in general not just the OP. GPS systems are not guaranteed to be accurate. It is not guaranteed that you are within the uncertainty the device specifies. There are different things that affect the accuracy of the position fix. Some things (i.e. few visible satellites) the device can work into it's error estimate, and some (i.e. reflections off cliffs) it cannot. The worst case I, personally, have seen was a device from a reliable manufacturer that gave an uncertainty of 25m, but a position that was wrong by >600m. 600m is a long way in the Cuillins. So GPS devices are reliable, but not infallible, and it is well worth understanding how and when they can fail. Just as you would for normal methods of navigation.
> This now means that I won't have to take my old garmin house brick as location back up ever again
Though your garmin is probably waterproof, fairly shockproof, and has a much longer battery life than the phone. The app is better than nothing (especially as it is free and weightless if you already carry the phone), the garmin is probably better than the phone. Of course it's fine to use either (or neither), everyone makes their own choices about the amount of kit to carry, but I personally treat GPS as emergency kit and like my emergency kit to be robust.
Also, some things captain paranoia said bear repeating for the benefit of readers in general not just the OP. GPS systems are not guaranteed to be accurate. It is not guaranteed that you are within the uncertainty the device specifies. There are different things that affect the accuracy of the position fix. Some things (i.e. few visible satellites) the device can work into it's error estimate, and some (i.e. reflections off cliffs) it cannot. The worst case I, personally, have seen was a device from a reliable manufacturer that gave an uncertainty of 25m, but a position that was wrong by >600m. 600m is a long way in the Cuillins. So GPS devices are reliable, but not infallible, and it is well worth understanding how and when they can fail. Just as you would for normal methods of navigation.
Post edited at 01:20
In reply to Craigyboy13:
Not true. Systems are down at the centimetre level now but you need a local base station.
Not true. Systems are down at the centimetre level now but you need a local base station.
In reply to seaofdreams:
I stand corrected regarding the difference between precsion and acuracy (sp).
I assumed an OS 6 fig ref gives 100m square, 8 would give a 10m square hence 10 figures give a 1metre square, but happy to be corrected.
> 10 figure (I assume you mean 12) is a precsion of 1 m not an acuracy.
I stand corrected regarding the difference between precsion and acuracy (sp).
I assumed an OS 6 fig ref gives 100m square, 8 would give a 10m square hence 10 figures give a 1metre square, but happy to be corrected.
In reply to Dan Arkle:
And haven't done since May 2000 (Google "selective availability" for more details). It's funny how these old factoids sometimes refuse to die.
GPS accuracy is more complicated that a single number. GPS is more complicated than simply being a dedicated pocketable device or a feature on a mobile phone. The top level Wikipedia article about GPS is a reasonable starting point for people who want to being to understand more about the subject, though I'm sure there are better sources out there.
Try GPS Test, it does both (you can select the grid system) and is also free: https://play.google.com/store/apps/details?id=com.chartcross.gpstest
> The americans no longer limit accuracy.
And haven't done since May 2000 (Google "selective availability" for more details). It's funny how these old factoids sometimes refuse to die.
GPS accuracy is more complicated that a single number. GPS is more complicated than simply being a dedicated pocketable device or a feature on a mobile phone. The top level Wikipedia article about GPS is a reasonable starting point for people who want to being to understand more about the subject, though I'm sure there are better sources out there.
> The free android app GPS Status gives you the accuracy estimate, I'm currently getting 9m indoors by the window. Unfortunately it doesn't convert to Nat Grid refs.
Try GPS Test, it does both (you can select the grid system) and is also free: https://play.google.com/store/apps/details?id=com.chartcross.gpstest
In reply to Ridge:
http://en.wikipedia.org/wiki/Accuracy_and_precision
My Garmin Forerunner often tells me that it's travelling at ~1kmph when it's just sat on my desk going nowhere. That's because of a mismatch between the accuracy of the GPS positional fix and the precision of the fix assumed by the logic that translates consecutive fixes in to a speed. GPS Test is currently telling me that my phone is travelling at 1mph sat on my windowsill; at the same time it's giving me a 10-digit grid reference. The two are logically incompatible but it doesn't really matter for general consumer purposes because (a) the user generally knows when they're stationery, and (b) when they're moving, a speed reading accurate to +/- 1mph is better than most vehicle speedometers (and better than a calibrated speedo in a police car, or a speed trap radar).
For more specialist purposes - arguably including hillwalking and mountaineering - if you only have a basic GPS device then you need to augment the information it gives you with information from other sources. Out in the hills that could be information such as: what you can see around you, and what your logic and reason tell you when you compare the GPS fix with a map. So eyes and a brain are a useful adjunct in those sorts of use cases.
> I assumed an OS 6 fig ref gives 100m square, 8 would give a 10m square hence 10 figures give a 1metre square, but happy to be corrected.
http://en.wikipedia.org/wiki/Accuracy_and_precision
My Garmin Forerunner often tells me that it's travelling at ~1kmph when it's just sat on my desk going nowhere. That's because of a mismatch between the accuracy of the GPS positional fix and the precision of the fix assumed by the logic that translates consecutive fixes in to a speed. GPS Test is currently telling me that my phone is travelling at 1mph sat on my windowsill; at the same time it's giving me a 10-digit grid reference. The two are logically incompatible but it doesn't really matter for general consumer purposes because (a) the user generally knows when they're stationery, and (b) when they're moving, a speed reading accurate to +/- 1mph is better than most vehicle speedometers (and better than a calibrated speedo in a police car, or a speed trap radar).
For more specialist purposes - arguably including hillwalking and mountaineering - if you only have a basic GPS device then you need to augment the information it gives you with information from other sources. Out in the hills that could be information such as: what you can see around you, and what your logic and reason tell you when you compare the GPS fix with a map. So eyes and a brain are a useful adjunct in those sorts of use cases.
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