We live in Cambridgeshire so a lot of our walking is not in the wilds but across agricultural land where good route planning and following is vital if you're not going to get the dogs set on you.

For this sort of walking I always used to rely on OS 1:25000 maps but lately I've been using a combination of Streetmap's 1:50000 maps and their sexy new interface, the Google Maps "satellite" imagery and the Merengo GPS route planner to do this.

Chatting to people at the Beddgelert meet at the weekend about the price of map software it dawned on me that this was something I should be sharing as what I'm using is all free. I wrote it up a while ago on my blog so rather than posting it all here here's a link if you're interested.

I should perhaps add that it only works if the area in which you're walking is one for which Google have aerial as opposed to satellite photography. They have for here (and for the area around Beddgelert as it happens) but lots of more rural areas are still only satellite imagery.

For planning purposes I use the Get-a-map function on OS site.

Gives clear topographical data and easy grid references. Works quite well.

I use this site, hit F11 and you have 1:50 000 map full screen on your pc. I quite often print new runs out using this.

http://www.bdcc.co.uk/XMarksTheSpot.htm 

Gary Perrin wrote (see)

I use this site, hit F11 and you have 1:50 000 map full screen on your pc. I quite often print new runs out using this.

http://www.bdcc.co.uk/XMarksTheSpot.htm 

Ooooh, that's nice. They're breaking the OS mapping out of the Multimap site. Looking at the code that's generating the page it looks like it may be legit too (rather than being something tricky which Multimap may close down at any time).

Thanks, I can see me switching to using that.

Now what I really want it to be able to do the waypoint entry to create my GPX file on top of an OS map rather than Google "satellite" imagery. Hmmm ... I must look at the Merengo code - perhaps I could cobble something together.

LHOON wrote (see)

For planning purposes I use the Get-a-map function on OS site.

Gives clear topographical data and easy grid references. Works quite well.

Will it produce larger maps than the default window (which is a bit small, 4km x 4km)?

The scrolling is a bit old fashioned too compared to the new Streetmap site or Multimap (including Gary's version). Drag scrolling is very cool so long as you've got the bandwidth on your Net connection.

Gary, that site's brilliant .

I know jack about computer code though. Is it totally legit then?

I'd have thought OS and Multimap would be having kittens if anyone can get free OS mapping for the whole of the UK.

Phil S wrote (see)

...

Is it totally legit then?

I'd have thought OS and Multimap would be having kittens if anyone can get free OS mapping for the whole of the UK.

To display the map by itself outside a MultiMap envelope needs a fee-based commercial service, as per the T&Cs:-

Licensing restrictions imposed by our data suppliers mean that users are not permitted to display the maps within their own website - even if the user is linking to our website behind the image. However, maps without our advertising or branding are available for a fee.

Phil S wrote (see)

Gary, that site's brilliant .

I know jack about computer code though. Is it totally legit then?

I'd have thought OS and Multimap would be having kittens if anyone can get free OS mapping for the whole of the UK.

Streetmap have long offered free OS 1:50K mapping of the whole of the UK, but they've never had the same high profile as Multimap but now it looks like Multimap are offering it too, which they didn't used to.

Looking into this some more Multimap now have an Open API which lets you do the sort of "mash ups" that Gary pointed us at. It's excellent news as it means they're trying to compete with Google Maps and it means this sort of site is very likely to be legit.

Tall Paul wrote (see)

Streetmap have long offered free OS 1:50K mapping of the whole of the UK, ...

Yes - but just like MultiMap, it had to be displayed in a separate StreetMap window accompanied by StreetMap advertisements, that's how the system works for all sites of this type (with UK mapping, that is).

Geoff C wrote (see)

Yes - but just like MultiMap, it had to be displayed in a separate StreetMap window accompanied by StreetMap advertisements, that's how the system works for all sites of this type (with UK mapping, that is).

I've tracked down the Open API T&C now and based on that it looks like Gary's site is legit: it shows the copyright link at the bottom and the Multimap branding at the top, both of which are as required.

There's an interesting posting from last September on their blog which shows the sort of thing they think it might be able to do: they used GPS track data to overlay onto a Multimap OS 1:50K map. Kewl.

I really am going to have to spend some time looking at what might be possible to bolt together with this API.

Gary Perrin wrote (see)

I use this site, hit F11 and you have 1:50 000 map full screen on your pc. I quite often print new runs out using this.

http://www.bdcc.co.uk/XMarksTheSpot.htm 

Created by a colleague of mine who's into mapping in a fairly big and active way.  I first posted a link here.  Bear in mind that the mapping has been transformed to local magnetic north; that's why the grid lines are on the wonk.

You might also like to have a look at Maptasm, or this OpenSpace Demo.

Or OpenStreetMap.

Well http://www.bdcc.co.uk/XMarksTheSpot.htm  is my code - its been around a while now. If you Shift+Right-click you can get a URL link to the spot you clicked (which displays with a big red X).

My efforts now are focused on http://wheresthepath.googlepages.com/wheresthepath.htm

The (only ?) advantage of the Multimap OpenAPI over the OS OpenSpace API is that it does not have such a lowly limit on daily tile rendering.

About North ...

On Multimap, OS1:50K maps have been reprojected so that true north is straight up the bowser window. This means that the OS grid lines, the verticals of which point to grid north, are no longer vertical (and the horzontals no longer horizontal!). This is nothing to do with magnetic north.

The difference getween grid north and true north is known as convergence. Center of sheet convergence values are, I believe, printed on the marginalia of OS 1:50K maps.

It's a shame that the best web maps API (Google's) does not legally support OS 1:50K maps as Multimap provide via their Open API.  

> On Multimap, OS1:50K maps have been reprojected so that true north is straight up the bowser window

Ah, sorry, Bill; yes, it's True North, not mag north.  My misunderstanding of what re-projection they'd applied.

Finally got round to looking at this thread properly. Concidentally I was using Google Earth earlier this evening to help plan a route for this weekend in the Brecon Beacons - the quality of images has recently been massively improved for the whole BBNP and surrounding areas - but it meant playing around on the computer as well as route-finding on the 1:25k hard copy map. Bill's website is simply awesome for browsing possible routes for future walks and working out what's feasible much more effectively than just using the map or Google Earth.

Fantastic site!