[Talk-GB] Finding Unmapped public rights of way

[Steven Horner]

I did a little bit of work early this morning on this for County Durham but
its very rough and nowhere near 100% accurate but gives a good idea of the
status of PRoW mapped in the area.

If you have a look at the 2 images linked below they show PRoW in County
Durham, one with background mapping, the other without. Green are PRoW
mapped in OSM, Red are PRoW not mapped in OSM.

Durham PRoW Status (No Background
map)<https://docs.google.com/file/d/0B4e_k58ZelMMaUgwLTdiR29iblU/edit?usp=sharing>
Durham PRoW Status (Stamen
Map)<https://docs.google.com/file/d/0B4e_k58ZelMMS2l3UmlqNmFtTTg/edit?usp=sharing>

This is very far from 100% accurate, but from visual inspection was quite
close.

I created this in QGIS comparing the OSM data to the PRoW released from
Durham County Council, I created a special query using intersects. This is
why it's not perfectly accurate because if an OSM mapped math intersected
with the PRoW data it would show up green, even though it may not be that
actual PRoW. A lot more work could be done to make this more accurate but
this was done in about 90 minutes this morning and most of that time was
spent converting OSM files and filtering out data I did not need.

I intend to write up what I did to create this, rough notes already done
and this may help others and hopefully someone can think of a much better
way. I am a beginner at most of this.


On Sun, Jul 28, 2013 at 2:05 AM, Craig Wallace <craigw84 at fastmail.fm> wrote:

> On 2013-07-27 13:11, Dudley Ibbett wrote:
>
>> Hi
>>
>> I'm trying to make use of the row files on rowmaps for derbyshire and
>> staffordshire and and merging these with and osm map file to then
>> produce maps that can highlight which paths are and aren't mapped.  I
>> can put the derbyshire file into JOSM and download parts of the area and
>> merge them to create an osm file that I can then save locally and import
>> into Maperative.  A modified rules file allows me to produce the prow
>> footpath ways and the osm footpath ways as different coloured dotted
>> lines so I can see which are/aren't mapped.  Unfortunately JOSM doesn't
>> seem to be able to cope with merging large files.  I maybe asking to
>> much of it as the files are quite big.  What I would like is to be able
>> to get a merged file of the derbyshire, saffordshire row files and the
>> equivalent osm map file on a regular basis (highlighting the rows that
>> aren't mapped) so I can slowly pick away at the remaining footpaths the
>> need mapping in this area.  Does anyone know of a simple way to do this?
>>
>
> Depends on how big the files are, and how much memory you have on your
> computer. You can assign more memory to JOSM, which might help. eg run it
> with a command like this:
> java -Xmx1500M -jar josm-tested.jar
> That would allow it 1500MB.
>
>
> Or for merging large files, you could use Osmosis.
> http://wiki.openstreetmap.org/**wiki/Osmosis<http://wiki.openstreetmap.org/wiki/Osmosis>
> ie use a command like this:
> osmosis --rx file2.osm --rx file1.osm --m --wx merged.osm
>
> Craig
>
>
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