[talk-au] National borders (was: import of state borders?)

[Brett Russell]

Hi
 
I have noticed that in Devonport Tasmania the coastline has appeared with reference ABS-2006 along with an area called beach.  It can be a little out so just curious what level of detail/accuracy is this and worthwhile better aligning it.  Also am I correct to assume that it is the high water mark?
 
Cheers Brett
 

> From: inas66+osm at gmail.com
> Date: Tue, 18 Sep 2012 09:34:46 +1000
> To: ohrosm at gmail.com
> CC: talk-au at openstreetmap.org; cadmanager at live.com.au
> Subject: Re: [talk-au] National borders (was: import of state borders?)
> 
> Hi,
> 
> If I understand correctly, the differences should only correspond to
> the amount that our coastline differs from the low water mark? Are we
> missing parts of the true coastline, is our coastline just inaccurate
> do you think?
> 
> I'd be surprised if there was any definitive low water mark data for
> the entire coastline.
> 
> Should we start with a simpler section, like NSW?
> 
> Ian.
> 
> On 12 September 2012 23:04, Michael Krämer <ohrosm at gmail.com> wrote:
> > Hi,
> >
> > 2012/8/31 Michael Krämer <ohrosm at gmail.com>
> >>
> >> 2012/8/31 Ian Sergeant <inas66+osm at gmail.com>
> >>>
> >>>
> >>> Well, I think the baseline is defined here..
> >>>
> >>> http://www.comlaw.gov.au/Details/F2006L00525
> >>>
> >>> I don't think we have any issues using those facts as a source.
> >>
> >>
> >> That looks great, combining this with the coastline should work. The
> >> coastline can be either drawn via osmosis from a planet extract or perhaps
> >> also from OverpassAPI. But I guess we'll have to generate all those line
> >> segments in QGIS to get the coordinate systems right.
> >
> >
> > A quick update from my side on this: I'm afraid it's not as straightforward
> > as I had assumed...
> >
> > I managed to generate an osm file from the points given in the proclamation
> > [1]. This gives the straight pieces of the baseline. But the problem is that
> > the coastline doesn't really give the right baseline for the rest (high vs.
> > low water mark). When I checked briefly I came across some pronounced
> > differences for example in the gulf of carpentaria. I guess it will be the
> > same along the Great Barrier Reef.
> >
> > So we would have to do some guesswork to combine coastline and straight
> > segements.
> >
> > BTW, it's very likely not a projection issue. I made sure by doing a check
> > of my calculations against the data Geoscience Australia provides.
> >
> > Michael
> >
> > -------
> > [1] https://dl.dropbox.com/u/1222615/baseline.osm
> 
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