[talk-au] Missing streets in Sydney

Andrew Harvey andrew.harvey4 at gmail.com
Thu Sep 15 11:24:12 BST 2011


Stephen's reply is pretty spot on. But also,

On Thu, Sep 15, 2011 at 10:49 AM, Ian Sergeant <inas66+osm at gmail.com> wrote:
> Of all the ways in Australia, less than 50% have source tag for how the
> location/name information was derived.
>
> Of those that do, around half indicate some form of imagery was used as the
> source (it seems that we are a country of tracers :-).

Perhaps that is because, unlike some other countries, we have high
resolution, accurate and current imagery that we can trace under a
free license --nearmap. If you have these 4 components and you combine
it with doing a ground survey just before or after tracing, then why
wouldn't you trace? The resulting data is more accurate than your
consumer GPS and just as recent. On the plus side your (or at least
my) overall mapping is more efficient so you can do more. In my
opinion.

> Interestingly enough, around a quarter of ways traced from imagery are
> named, with no source tag indicating of how the name of the way was derived,
> could you say that at least some of these have been surveyed without being
> tagged accordingly?  Or could you even think something more sinister?

... and how many of my ways traced from imagery and named have no
source tag indicating how the name was derived and how the location of
the feature was derived?

If there is no source tag you can't know if the name was from a ground
survey, or just copied from a non-free source. I've encountered both
situations before, and just reinforces why I try to encourage
contributors to add source information. I can't really do anything
else except for going out doing the survey and subsequently adding a
source tag, so I suggest you try to help be part of the solution and
add source information to all the data you add.

> My conclusion - there is no way I can see in Australia to reliably construct
> a surveyed or traced data-set based on the tagged source information as it
> now exists.

Yep I agree. I've tried my best with my edits to allow for that, but
others are free to do as they wish so long as they are really using
free data. The only way forward I see is improve the database by
adding in your own source tags when they are missing as you re-survey
things.



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