[Talk-GB] 10 fascinating facts about OSM & OSGB
oliver.jowett at gmail.com
Thu Apr 18 15:40:47 UTC 2013
On Thu, Apr 18, 2013 at 3:02 PM, Chris Hill <osm at raggedred.net> wrote:
> On 18/04/13 14:14, Shaun McDonald wrote:
>> On 18 Apr 2013, at 13:01, "Dave F." <davefox at madasafish.com> wrote:
>> On 18/04/2013 12:52, Shaun McDonald wrote:
>>>> Updates are a lot harder to do as you have to deal with differences
>>> When you say differences, do you mean within the tags? Does it need to
>>> do that, could it not do a simpler find & replace?
>> If someone has modified the item in OSM and in NaPTAN then it needs
>> manual intervention as to which is more correct - the one in OSM or the one
>> in NaPTAN.
>> There are various errors in NaPTAN data. The data was created by
> different means in different local authorities and to varying standards of
> quality. The position is not always very accurate, but sometimes the
> accompanying information can be poor too. Some data are very good, but
> until you survey it you just don't know. As someone who has manually
> validated every stop in in a city (~1300) and about a third (~900) of the
> stops in a large Unitary Authority I can vouch for the differences and the
> wide variation in quality. It became clear that in the city the quality
> varied from area to area. I suspect that some areas were surveyed or
> recorded or checked more diligently than others possibly because a more
> diligent or competent person did the work there.
Can I ask what type of changes you made to the NaPTAN data when manually
validating the stops?
I've been meaning to look at exactly this - updating the NaPTAN imported
data - for a little while now as it's needed before the TNDS data (which
has route / timetable info) can be usefully used.
My rough plan was to assume that all tags under the naptan: namespace were
fair game for updating to match the current NaPTAN import. Whether that's
practical will depend on if there have been widespread manual changes to
the naptan: data or not.
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