http://www.grough.co.uk/magazine/2014/09/17/gps-pressure-leads-ordnance-survey-to-ponder-map-co-ordinates-change

OK, so not goodbye, but an interesting move…

The organisation stressed it is not changing its national grid references, which are used by most outdoor enthusiasts, but may change the lat and long datum to the WGS84 model

Interesting move, but fairly sensible. I think WGS84 is used pretty universally in the West at least.

hmmm.

French IGN have added WGS84 to all their maps for the last few years. They have retained both lat & long (NTF using Parisien meridian) on the sheet and lat & long around the perimeter of the sheet in RGF93.

I dont see why OS cant retain OS grid ref datum in blue, and maybe add WGS84 in purple say or just around the perimeter and at mid sheet repeaters.

I don’t see why OS can’t retain OS grid ref datum in blue, and maybe add WGS84 in purple

Can I request two colours that are significantly different rather than just shades of the same? 😀

How about red and green so that at night you can switch between a red or green led light when night-navigating depending on which grid system youre using. And the colourblind can just go and get lost. 🙂

You can tell OS what you think here: http://www.ordnancesurvey.co.uk/blog/2014/09/proposed-changes-to-latitude-and-longitude-representation-on-paper-maps-tell-us-your-thoughts/

(Well you could if the site was working)

Matt are you a newspaper journalist? Your headline is wildly unlike the actual article.

#clickbait on Singletrack???

matt – You should be a Daily Fail journo. 🙂

There is absolutely no intention to get rid of grid references.

This is simply about changing the datum to the widely used WGS 84. I don’t know anyone who uses lat and long top navigate with an OS map anyway.

Not all that interesting either, as it’s not going to affect 99.9% of people who already set their GPS to use OS Grid References – a facility which is available wherever you bought your GPS unit. What’s more, in order to convert between WGS84 and OS Grid you’re still going to have to go via Airy 1830, as that’s what the OS Grid is defined against. I can’t actually see what advantage it brings either, as if for some reason you wanted to use lat/long it’s not hard to set a different datum and we are a nice convenient island where there is no need to switch datums at some arbitrary border.

It’s not even true that WGS84 is universal – in the US where maps have lat/long coordinates rather than grid references they use UTM projections.

#clickbait on Singletrack???

“This Man Read a Map: YOU WON’T BELIEVE WHAT HAPPENED NEXT!”

“17 Reasons Why Maps Hate You”

“What Kind Of Map Are You? Take Our Test”

This article does make one issue occur to me. If Scotland had become independent would they have had to set up their own mapping agency, and if so would they have used a different projection, given that Airy 1830 is good for the UK as a whole or England in isolation, but distorts things a bit in the North of Scotland 😈

Isn’t the datum set according to whatever sphere best fits the earths surface at that point (the earth being not speherical and actualy quite lumpy).

Having said that how do they project OS maps, on charts the grid lines converge to the top so that at any point on the chart the scale is the same, how do OS project it, does map north deviate more or less from magnetic north depending on where you are on the map? So if you change datum then you’d also change the refernee point for ‘north’?

distorts things a bit in the North of Scotland

Funnily enough the weather map projection is the source of some annoyance in Scotland, because it is just a little bit southern-centric:

Compared to a straight projection:

grid to magnetic to true north all vary by longitude.

EDIT: “Correct” in what sense? Proportionate to what?

EDIT: “Correct” in what sense? Proportionate to what?

“Correct” as in looking straight down at the center of the country to make the lat/long grid as square as possible, so that a hundred miles in Scotland is roughly the same as a hundred miles in Southern England.

Rather than picturing the country at an angle best seen from a hot air balloon somewhere above Paris 😀

Honey I Shrunk the Country!

because it is just a little bit southern-centric:

Population centric.

Of all the things worth getting annoyed about, this is pretty far down the list. You could always listen to the spoken forecast instead, where the North of Scotland ALWAYS gets a mention even though hardly anyone lives there. Why? Because the weather’s often different and that deserves a mention. If anything that demonstrates that the weather people DO care about Scotland.

well while we’re watching the world burn, Graham, why dont we turn it upside down as well! 😀

Of all the things worth getting annoyed about, this is pretty far down the list. You could always listen to the spoken forecast instead

Indeed – but that image is from what most people regard as the main forecast from the UK-wide public broadcaster.

It’s not that folk in Scotland don’t know what the weather will be – I suspect most use local forceasts for that as the BBS one is waaay to general – the issue is more that they chose an unnatural projection which put huge emphasis on the south to the detriment of the north.

It is indicative of a mindset that in this case quite literally belittles the north of the country.

why dont we turn it upside down as well

Tried that for a bit, but all the blood went to my head.

[video]https://www.youtube.com/watch?v=2lR7s1Y6Zig[/video]

(ans also http://xkcd.com/977/ )

It is indicative of a mindset that in this case quite literally belittles the north of the country.

I don’t think it is – otherwise, they wouldn’t talk about it as much as they do.

The past few months aside molgrips, I really don’t think that they do.

That weather map is really annoying wherever you live.

I don’t think it was deliberately chosen annoy the Scots.

I don’t think it was deliberately chosen annoy the Scots.

It was probably early preparation for an expected ‘Yes’ vote.

I don’t think it was deliberately chosen annoy the Scots.

I’m not suggesting it was.

But I do think it was chosen for the South, without really caring* whether it might annoy anyone north of Leeds.

.

*Hanlon’s razor

The past few months aside molgrips, I really don’t think that they do.

The weather forecast does. Or are you saying you don’t listen when it’s about Scotland? Typical bias from you English scum!

😉

I think there is a bit of misunderstanding going on, as far as I can see they are just proposing to change the lat long coords printed around the edge of their maps to use the WGS84 datum, I doubt this would affect even 1% of OS map users.

It’s not even true that WGS84 is universal – in the US where maps have lat/long coordinates rather than grid references they use UTM projections.

That’s incorrect, WGS84 is used globally. We use UTM projections here in the UK too, either with the WGS84 datum or for example ED50, ETRS89, etc, depending what the usage of the data is.

Having said that how do they project OS maps, on charts the grid lines converge to the top so that at any point on the chart the scale is the same, how do OS project it, does map north deviate more or less from magnetic north depending on where you are on the map? So if you change datum then you’d also change the refernee point for ‘north’?

OSGB uses a transverse mercator projection http://epsg.io/27700 , whereas charts generally use a mercator projection where the parallels don’t converge, I think so bearings can be used in navigation without issue from earth curvature. This means scale varies with distance from the equator – on a mercator chart a 100km scale bar can not be referred to at the equator and then around the UK for example, and the scale becomes infinite at the poles. Some more localised charts don’t use mercator, it will be stated on the chart.

It’s certainly bloody annoying if you’re doing LeJog and you start thinking you’re almost there by the time you reach Manchester!

Stoner – Member

well while we’re watching the world burn, Graham, why dont we turn it upside down as well!

[video]http://www.youtube.com/watch?v=n8zBC2dvERM[/video]

Matt are you a newspaper journalist?

clickbait

Someone had left a Daily Mail on my desk this morning, maybe it influenced me? 😕

Having met Matt – I can re-assure the STW Massive that he has a healthy disregard for Daily Fail attitudes so I can only assume that the Lizard people have finalay found his hiding place. He does live in Dublane right enough… 😆