[Proj] Belge 1972 / Belgian Lambert 72 (31370)
gordon.johnston at exxonmobil.com
gordon.johnston at exxonmobil.com
Thu Jan 28 12:15:47 EST 2010
Roger, there are test RD to ETRS89 values included in the European
Coordinate Reference Systems website at
http://www.crs-geo.eu/nn_124392/crseu/EN/CRS__Description/crs-national__node.html?__nnn=true
go to the bottom of the page and follow the verification button.
It also briefly notes that the Belgian Lambert 2005 was only in use for
about 4 months. See:
http://www.crs-geo.eu/nn_124226/crseu/EN/CRS__Description/crs-national__node.html?__nnn=true
BTW the Euro CRS site is best started from here:
http://www.crs-geo.eu/nn_124226/crseu/EN/CRS__Description/crs-national__node.html?__nnn=true
Regards
Gordon Johnston, UK
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Today's Topics:
1. Re: Belge 1972 / Belgian Lambert 72 (31370)
-towgs84parameters (Jan Hartmann)
2. undefined cache functions (Matthias Schneider)
3. Re: EPSG:27700 (Nick Hopton)
4. Re: Belge 1972 / Belgian Lambert 72 (31370)
-towgs84parameters (Roger Oberholtzer)
----------------------------------------------------------------------
Message: 1
Date: Thu, 28 Jan 2010 10:51:20 +0100
From: Jan Hartmann <j.l.h.hartmann at uva.nl>
Subject: Re: [Proj] Belge 1972 / Belgian Lambert 72 (31370)
-towgs84parameters
To: "PROJ.4 and general Projections Discussions"
<proj at lists.maptools.org>
Message-ID: <4B615E18.8090205 at uva.nl>
Content-Type: text/plain; charset="iso-8859-1"
Hi Thibaut,
Why did they do this in 2005? In Holland we still use the RD system with
the Bessel ellipse. Nowadays, there is no problem at all in converting
from whatever projection and datum to WGS84. Before 2005 you had to
convert from Lambert 1972, after that from Lambert 2005, and now you
have to add 500000 to each coordinate. Given that you can convert from
every system, why going to the hassle of changing the datun and zero
point of an existing Lambert system, only to end up with something that
also has te be converted to WGS84?
Jan
On 28-1-2010 9:20, Thibaut Gheysen wrote:
> Hi,
>
> The development of the Lambert coordinate system 2005 follows the
> introduction of ETRS89 in Europe. From 1989 to 2002, the IGN has
> reviewed the national geodetic network using the GPS network. This
> changes has led to the Lambert 2005 projection. For a given location,
> the difference between the coordinates in Lambert 1972 and 2005 are
> relatively low (+ / - 1 kilometer). Considering this small difference,
> when we received map data in Lambert 2005 without the coordinate
> system used has been specified, you might think, if you don't pay too
> much attention, that the data were still in Lambert 1972. Therefore,
> the IGN has added 500 kilometers in X and Y (Lambert 2008) : you see
> thus immediately that the projection system used is no longer the
> Lambert 1972.
>
> Thibaut.
>
>
> 2010/1/27 Jan Hartmann <j.l.h.hartmann at uva.nl
> <mailto:j.l.h.hartmann at uva.nl>>
>
>
> Nice. Our Belgian friends seem to have changed their national
> projection. I don't understand this page (Dutch:
> http://www.ngi.be/FR/FR4-4.shtm; French:
> http://www.ngi.be/FR/FR2-1-7.shtm, no English need apply). It says:
>
> "Due to the too small deviation (1 kilometer) between the
> coordinates of
> the Lambert 1972 projection and those of the Lambert 2005 projection,
> the NGI has changed the parameters of the Lambert 2005 projection,
and
> created the Lambert 2008 projection".
>
> What they did was just adding 499.000 to both x and y coordinates of
> Lambert 2005.
>
> Lambert 1972 is the projection as defined in PROJ's epsg file (nr
> 31370), derived from the EPSG database (coordinate reference nr 411).
> Its datum is intl (=Hayford). First standard parallel is 51.166667,
> second standard parallel 49.833333, central parallel 90 (?), central
> meridian 4.367486666. x_0 = 150000.01256, y_0 = 5400088.4378
>
> Lambert 2005, as defined on the above page (nothing in the EPSG
> database): datum GRS80 (=WGS84, approximately). First standard
> parallel
> 51.166667, second standard parallel 49.833333, central parallel
> 50.7977777, central meridian 4.35916666666. x_0 = 150328, y_0 =
166262
>
> Lambert 2008 is Lambert 2005 Hi,with 499 km added to both x and y
> coordinates
>
> So, without additional information, I really don't see the
> relationship
> between the 1972, 2005 and 2008 systems. What's the difference
between
> 1972 and 2005, and why did they add 500 km in 2008? Did they
> change each
> and every coordinate on each and every Belgian map in 2005 and are
> they
> changing it again in 2008? Has anyone ever seen a Lambert 2005
> coordinate? They are not in the EPSG database.
>
> If anyone can make sense of this gobbledygook, I would be happy to
> know.
>
> Jan
>
>
>
>
> On 27-1-2010 20:12, OvV_HN wrote:
> >
> > ----- Original Message ----- From: "Jan Hartmann"
> <j.l.h.hartmann at uva.nl <mailto:j.l.h.hartmann at uva.nl>>
> > To: "PROJ.4 and general Projections Discussions"
> > <proj at lists.maptools.org <mailto:proj at lists.maptools.org>>
> > Cc: "OvV_HN" <ovv at hetnet.nl <mailto:ovv at hetnet.nl>>
> > Sent: Wednesday, January 27, 2010 7:59 PM
> > Subject: Re: [Proj] Belge 1972 / Belgian Lambert 72 (31370)
> > -towgs84parameters
> >
> >
> >> Thanks Oscar, good to know. How did you find this page? Is it
> >> reachable from within the ngi site or did you find it with Google.
> >>
> >> Jan
> >>
> >
> >
> > The path starting from the Dutch language home page is:
> > home > know-how > geodetische diensten > Lambert 2008
> > http://www.ngi.be/NL/NL2-1-7.shtm
> >
> > Scroll down to:
> > "Relatie tussen de geodetische referentiesystemen van 1972 en 2008"
> > ...
> > "> uitgebeider schema in pdf"
> >
> > This last link goes to the page I mentioned.
> >
> >
> > Oscar van Vlijmen
> >
> >
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Message: 2
Date: Thu, 28 Jan 2010 11:20:15 +0100
From: Matthias Schneider <schneider.matthias at tu-ilmenau.de>
Subject: [Proj] undefined cache functions
To: "PROJ.4 and general Projections Discussions"
<proj at lists.maptools.org>
Message-ID: <4B6164DF.7070903 at tu-ilmenau.de>
Content-Type: text/plain; charset=ISO-8859-15; format=flowed
Hi,
when I try to build the proj4 4.7.0 with Visual Studio 2005 I got some
warnings which I have to solve:
********************
1>.\src\proj-4.7.0\src\pj_init.c(119) : warning C4013:
'pj_search_initcache' undefined; Assumption: extern with return type int
********************
There are several problems related to "pj_insert_initcache",
"pj_acquire_lock" and "pj_release_lock".
Is there a solution for that problem? I found nothing so far. With 4.6.1
everything runs fine :(
Regards,
Matthias
------------------------------
Message: 3
Date: Thu, 28 Jan 2010 10:36:12 +0000
From: Nick Hopton <nhopton at gmail.com>
Subject: Re: [Proj] EPSG:27700
To: proj at lists.maptools.org
Message-ID:
<304bf2491001280236k1ee9edc0i2c8fefc2050e04d1 at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Jose wrote:
> I think datum definition is not included in the epsg file when there
> are different sets of parameters or forms of transformation from the
> local datum to WGS84. +datum=OSGB36 corresponds to a given set of
> parameters, which may not be the most appropriate for some
> applications. You can also do the datum transformation using NTv2
> grids instead of Bursa-Wolf transformation (see for example
> http://lists.maptools.org/pipermail/proj/2006-November/002658.html).
> Users are free to combine projection 27700 with their own datum
> transformation. You can have for example:
>
> cs2cs +init=4326 +to +init=27700 +datum=OSGB36
> or
> cs2cs +init=4326 +to +init=27700 +towgs84=.....
> or
> cs2cs +init=4326 +to +init=27700 +nadgrids=c:/england-wales.gsb
>
> Regards
Thanks for this. I think that EPSG: 27700 is specific to the Ordnance
Survey of Great Britain and is meant to stand alone. People using Proj
to project or reproject from or to 27700 will be getting errors in
excess of a hundred metres, which is a large enough error to cause
problems, but not necessarily large enough to be noticed at first
sight.
Regards,
Nick.
------------------------------
Message: 4
Date: Thu, 28 Jan 2010 14:21:15 +0100
From: Roger Oberholtzer <roger at opq.se>
Subject: Re: [Proj] Belge 1972 / Belgian Lambert 72 (31370)
-towgs84parameters
To: "PROJ.4 and general Projections Discussions"
<proj at lists.maptools.org>
Message-ID: <1264684875.17560.34.camel at acme.pacific>
Content-Type: text/plain; charset="UTF-8"
On Thu, 2010-01-28 at 10:51 +0100, Jan Hartmann wrote:
> Hi Thibaut,
>
> Why did they do this in 2005? In Holland we still use the RD system
> with the Bessel ellipse.
OOC, how do you configure proj for RD? I am using this (WGS84 Lat/Long
is the source) in the C-API:
"+proj=sterea "
"+lat_0=52.15616055555555 "
"+lon_0=5.38763888888889 "
"+k=0.9999079 "
"+x_0=155000 "
"+y_0=463000 "
"+ellps=bessel "
"+towgs84=565.040,49.910,465.840,-0.40939,0.35971,-1.86849,4.0772"
"+units=m "
"+no_defs"
I just want to verify that nothing has gone wrong in my library. Bit rot
and all that.
Is there a good (official?) set of test data for RD? Something that has
WGS84 lat/longs, and the corresponding RD northings/eastings. I can
never have too many tests!
--
Roger Oberholtzer
OPQ Systems / Ramb?ll RST
Ramb?ll Sverige AB
Krukmakargatan 21
P.O. Box 17009
SE-104 62 Stockholm, Sweden
Office: Int +46 10-615 60 20
Mobile: Int +46 70-815 1696
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