[Talk-GB] bing image alignment

[ael]

On Sat, Sep 14, 2013 at 02:24:31PM +0100, OpenStreetmap HADW wrote:
> On 13 September 2013 19:59, ael <law_ence.dev at ntlworld.com> wrote:
> 
> > No one has mentioned the OS gps (passive) stations: for example
> > http://www.openstreetmap.org/browse/node/472420260
> > http://www.ordnancesurvey.co.uk/business-and-government/help-and-support/navigation-technology/os-net/surveying.html
> >
> > Can we not use them at least for some reference points?
> 
> Interesting.  Unfortunately it looks as though OS Net slipped past
> their commercial people as they use the term "freely available" on
> their web site without giving a precise legal definition of what that
> means.  Given the intended use (all high accuracy surveys in the UK)
> there seems to be an implication that they aren't claiming a database
> copyright, but OSM will probably need a clearer legal statement.
> OSTN02 seems to have the same licensing uncertainty.

It is a few years since I looked at any of this, but it had not occurred
to me that any copyright issue could arise. They are essentially modern
trig points. There is a mark on the ground, and their website publishes
the coordinates. Using these coordinates to position a node on osm
would constitute republishing? I thought very small extracts of
copyrighted material were permitted in any case.

> Depending on exactly which ground feature represents the station, 

That one is a small stud at ground level on a small concrete block 
all surrounded by a rectangular metal fence maybe 30cm high, roughly 1m by
1/2m. I must dig out a photograph.

> Are the ETRS89 coordinates given on the monument itself, as they would

As far as I recall, there was no indication whatsoever of what it was
nor any text at all.

> It's a pity they aren't all clearly visible on the aerial view, my
> local one, which appears to be within centimetres of Bing, is only

I would be very surprised if the one at Buckland could be seen in aerial
images. I must check. It is quite easy to miss it on the ground 
unless you know what you are looking for and where to look. The tall
grass was enough to hide it.

The biggest problem seems to be that there are only a few on public
land and widely scattered, so of limited use.

ael