[GRASS-dev] projection NC sample data set

Hi, on https://grass.osgeo.org/download/sample-data/ it is suggested that the projection of the NC sample data set is NAD83(HARN) / North Carolina ( EPSG 3358). However, according to the projection information of the sample dataset it self, the projection is Lambert Conformal Conic.

The description on http://georepository.com/ reads that NAD83(HARN) / North Carolina uses the NAD83(HARN) geographic 2D CRS as its base CRS and the SPCS83 North Carolina zone (meters) (Lambert Conic Conformal (2SP)) as its projection. So I see where the LCC is coming from.

If, however, I create a new location with EPSG 3358, the name of the projection (g.region -p) is NAD83(HARN) / North Carolina.

Which of the two should be given / shown with g.region -p I am not sure, but I think it would be good to be consistent.

Paulo

On Wed, Apr 20, 2016 at 11:02 AM, Paulo van Breugel
<p.vanbreugel@gmail.com> wrote:

Hi, on https://grass.osgeo.org/download/sample-data/ it is suggested that
the projection of the NC sample data set is NAD83(HARN) / North Carolina (
EPSG 3358). However, according to the projection information of the sample
dataset it self, the projection is Lambert Conformal Conic.

http://epsg.io/3358
-->
    ...
    PROJECTION["Lambert_Conformal_Conic_2SP"],

The description on http://georepository.com/ reads that NAD83(HARN) / North
Carolina uses the NAD83(HARN) geographic 2D CRS as its base CRS and the
SPCS83 North Carolina zone (meters) (Lambert Conic Conformal (2SP)) as its
projection. So I see where the LCC is coming from.

If, however, I create a new location with EPSG 3358, the name of the
projection (g.region -p) is NAD83(HARN) / North Carolina.

GRASS 7.1.svn (nc_spm_08_grass7):~ > g.proj -c epsg=3358 location=nc_test
Location <nc_test> created
You can switch to the new location by
`g.mapset mapset=PERMANENT location=nc_test`

GRASS 7.1.svn (nc_spm_08_grass7):~ > g.mapset mapset=PERMANENT location=nc_test
Mapset switched. Your shell continues to use the history for the old mapset
You can switch the history by commands:
history -w; history -r
/home/neteler/grassdata/nc_test/PERMANENT/.bash_history;
HISTFILE=/home/neteler/grassdata/nc_test/PERMANENT/.bash_history

GRASS 7.1.svn (nc_spm_08_grass7):~ > g.proj -w
PROJCS["NAD83(HARN) / North Carolina",
    GEOGCS["grs80",
        DATUM["unknown",
            SPHEROID["Geodetic_Reference_System_1980",6378137,298.257222101],
            TOWGS84[0,0,0,0,0,0,0]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433]],
    PROJECTION["Lambert_Conformal_Conic_2SP"],
    PARAMETER["standard_parallel_1",36.16666666666666],
    PARAMETER["standard_parallel_2",34.33333333333334],
    PARAMETER["latitude_of_origin",33.75],
    PARAMETER["central_meridian",-79],
    PARAMETER["false_easting",609601.22],
    PARAMETER["false_northing",0],
    UNIT["Meter",1]]

It appears that GRASS/GDAL does not understand

        DATUM["NAD83_High_Accuracy_Reference_Network",

An issue for
https://trac.osgeo.org/grass/ticket/2456

Since we now read this information from GDAL, I'm rather lost why 3358
still fails to be recognized properly?!

Maybe https://trac.osgeo.org/grass/changeset/68131 is yet incomplete?

Markus

Hi,

On Wed, Apr 20, 2016 at 11:02 AM, Paulo van Breugel
<p.vanbreugel@gmail.com> wrote:

Hi, on https://grass.osgeo.org/download/sample-data/ it is suggested that
the projection of the NC sample data set is NAD83(HARN) / North Carolina (
EPSG 3358).

Some libproj parts got fixed in the last 24hs, please try again. It
now looks like this:

grass70 -c epsg:3358 ~/grassdata/nc_data
Cleaning up temporary files...
Creating new GRASS GIS location/mapset...

GRASS 7.0.4svn (nc_data):~/mundialis/ideas > g.proj -w
PROJCS["NAD83(HARN) / North Carolina",
    GEOGCS["grs80",
        DATUM["NAD83_High_Accuracy_Reference_Network",
            SPHEROID["Geodetic_Reference_System_1980",6378137,298.257222101]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433]],
    PROJECTION["Lambert_Conformal_Conic_2SP"],
    PARAMETER["standard_parallel_1",36.16666666666666],
    PARAMETER["standard_parallel_2",34.33333333333334],
    PARAMETER["latitude_of_origin",33.75],
    PARAMETER["central_meridian",-79],
    PARAMETER["false_easting",609601.22],
    PARAMETER["false_northing",0],
    UNIT["Meter",1]]

which should be right.

Best
Markus

PS: Kudos to Paul Kelly and Even Rouault for their help (via grass-dev
and personal emails)

On Tue, Apr 26, 2016 at 7:23 PM, Markus Neteler <neteler@osgeo.org> wrote:

Hi,

On Wed, Apr 20, 2016 at 11:02 AM, Paulo van Breugel
<p.vanbreugel@gmail.com> wrote:
> Hi, on https://grass.osgeo.org/download/sample-data/ it is suggested
that
> the projection of the NC sample data set is NAD83(HARN) / North Carolina
(
> EPSG 3358).

Some libproj parts got fixed in the last 24hs, please try again. It
now looks like this:

grass70 -c epsg:3358 ~/grassdata/nc_data
Cleaning up temporary files...
Creating new GRASS GIS location/mapset...

GRASS 7.0.4svn (nc_data):~/mundialis/ideas > g.proj -w
PROJCS["NAD83(HARN) / North Carolina",
    GEOGCS["grs80",
        DATUM["NAD83_High_Accuracy_Reference_Network",

SPHEROID["Geodetic_Reference_System_1980",6378137,298.257222101]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433]],
    PROJECTION["Lambert_Conformal_Conic_2SP"],
    PARAMETER["standard_parallel_1",36.16666666666666],
    PARAMETER["standard_parallel_2",34.33333333333334],
    PARAMETER["latitude_of_origin",33.75],
    PARAMETER["central_meridian",-79],
    PARAMETER["false_easting",609601.22],
    PARAMETER["false_northing",0],
    UNIT["Meter",1]]

which should be right.

Great, thanks, also to Paul Kelly and Even Roualt

Best
Markus

PS: Kudos to Paul Kelly and Even Rouault for their help (via grass-dev
and personal emails)