[GRASS-user] Question about Datum not recognised by GRASS

GRASS GRASS user
1

Hi,

I am quite new to GRASS and this is my first post, looking for some help
here!

I am now processing the dataset under *CGCS2000 / 3-degree Gauss-Kruger CM
120E*. But the dataset could not be recognised by GRASS when I trying to
import the DEM data. The warning message kept poping up:

WARNING: Datum <China_2000> not recognised by GRASS and no parameters found

And the output from g.region -p is:

projection: 99 (CGCS2000 / 3-degree Gauss-Kruger CM 120E)
zone: 0
datum: ** unknown (default: WGS84) **
ellipsoid: grs80
north: 1
south: 0
west: 0
east: 1
nsres: 1
ewres: 1
rows: 1​
cols: 1
cells: 1

How can I fix it?

Best,
Zac45

--
Sent from: http://osgeo-org.1560.x6.nabble.com/Grass-Users-f3884509.html

2

Sorry, the output of g.region -p is:
projection: 99 (CGCS2000 / 3-degree Gauss-Kruger CM 120E)
zone: 0
datum: ** unknown (default: WGS84) **
ellipsoid: grs80
north: 42.99666667
south: 41.54
west: 118.67083333
east: 121.465
nsres: 0.00083333
ewres: 0.00083333
rows: 1748
cols: 3353
cells: 5861044

--
Sent from: http://osgeo-org.1560.x6.nabble.com/Grass-Users-f3884509.html

3

Welcome

···

On 02/07/2020 20:58, Zac45 wrote:

Hi,

I am quite new to GRASS and this is my first post, looking for some help
here!

I am now processing the dataset under *CGCS2000 / 3-degree Gauss-Kruger CM
120E*. But the dataset could not be recognised by GRASS when I trying to
import the DEM data.  The warning message kept poping up:

Can you show the CRS of your original DEM before import into GRASS. What’s the output from:

gdalinfo <your_original_DEM>

?

WARNING: Datum <China_2000> not recognised by GRASS and no parameters found

And the output from g.region -p is:

projection: 99 (CGCS2000 / 3-degree Gauss-Kruger CM 120E)
zone:       0
datum:      ** unknown (default: WGS84) **
ellipsoid:  grs80
north:      1
south:      0
west:       0
east:       1
nsres:      1
ewres:      1
rows:       1​
cols:       1
cells:      1

How can I fix it?

Best,
Zac45

--
Sent from: [http://osgeo-org.1560.x6.nabble.com/Grass-Users-f3884509.html](http://osgeo-org.1560.x6.nabble.com/Grass-Users-f3884509.html)
_______________________________________________
grass-user mailing list
[grass-user@lists.osgeo.org](mailto:grass-user@lists.osgeo.org)
[https://lists.osgeo.org/mailman/listinfo/grass-user](https://lists.osgeo.org/mailman/listinfo/grass-user)

-- 
Micha Silver
Ben Gurion Univ.
Sde Boker, Remote Sensing Lab
cell: +972-523-665918
[https://orcid.org/0000-0002-1128-1325](https://orcid.org/0000-0002-1128-1325)
4
···

On 03/07/2020 11:53, 李泽浩 wrote:

Hi Micha,

Thanks for your reply! Here is the output from gdalinfo:
This DEM is projected from WGS84 to CGCS 2000 in ArcMap first and then imported in GRASS.

gdalinfo C:\Users\zhangtong\Desktop\Zehao_DEM.tif
Driver: GTiff/GeoTIFF
Files: C:\Users\zhangtong\Desktop\Zehao_DEM.tif
Size is 3353, 1748
Coordinate System is:
PROJCS[“CGCS2000_3_Degree_GK_CM_120E”,
GEOGCS[“GCS_China_Geodetic_Coordinate_System_2000”,
DATUM[“China_2000”,
SPHEROID[“CGCS2000”,6378137,298.257222101]],
PRIMEM[“Greenwich”,0],
UNIT[“degree”,0.0174532925199433]],
PROJECTION[“Transverse_Mercator”],
PARAMETER[“latitude_of_origin”,0],
PARAMETER[“central_meridian”,120],
PARAMETER[“scale_factor”,1],
PARAMETER[“false_easting”,500000],
PARAMETER[“false_northing”,0],
UNIT[“metre”,1,
AUTHORITY[“EPSG”,“9001”]]]
Origin = (118.670833333333334,42.996666666666670)
Pixel Size = (0.000833333333333,-0.000833333333333)
Metadata:
AREA_OR_POINT=Area
DataType=Generic
Image Structure Metadata:
INTERLEAVE=BAND
Corner Coordinates:
Upper Left ( 118.6708333, 42.9966667) (115d30’50.80"E, 0d 0’ 1.40"N)
Lower Left ( 118.6708333, 41.5400000) (115d30’50.80"E, 0d 0’ 1.35"N)
Upper Right ( 121.4650000, 42.9966667) (115d30’50.89"E, 0d 0’ 1.40"N)
Lower Right ( 121.4650000, 41.5400000) (115d30’50.89"E, 0d 0’ 1.35"N)
Center ( 120.0679167, 42.2683333) (115d30’50.84"E, 0d 0’ 1.37"N)
Band 1 Block=128x128 Type=Int16, ColorInterp=Gray
NoData Value=32767

OK, that looks good.

Now you can create a new LOCATION for your GRASS data using that DEM projection information as follows:
(I’ll assume you want your GRASS database under: C:\Users\zhangtong\grassdata)

grass -c C:\Users\zhangtong\Desktop\Zehao_DEM.tif -e C:\Users\zhangtong\grassdata\CGCS2000\PERMANENT

THis command creates a new LOCATION based on the DEM coordinate system, then exits (-e option).

Now start GRASS in that new location and you should be able to import your DEM without problem:

grass C:\Users\zhangtong\grassdata\CGCS2000\PERMANENT

and then at the GRASS command prompt:

r.import C:\Users\zhangtong\Desktop\Zehao_DEM.tif output=zehao_dem

g.region -ap rast=zehao_dem

Zac

Micha Silver <tsvibar@gmail.com> 于2020年7月3日周五 下午4:43写道：

On 02/07/2020 20:58, Zac45 wrote:

Hi,

I am quite new to GRASS and this is my first post, looking for some help
here!

Welcome

I am now processing the dataset under *CGCS2000 / 3-degree Gauss-Kruger CM
120E*. But the dataset could not be recognised by GRASS when I trying to
import the DEM data.  The warning message kept poping up:

Can you show the CRS of your original DEM before import into GRASS. What’s the output from:

gdalinfo <your_original_DEM>

?

WARNING: Datum <China_2000> not recognised by GRASS and no parameters found

And the output from g.region -p is:

projection: 99 (CGCS2000 / 3-degree Gauss-Kruger CM 120E)
zone:       0
datum:      ** unknown (default: WGS84) **
ellipsoid:  grs80
north:      1
south:      0
west:       0
east:       1
nsres:      1
ewres:      1
rows:       1​
cols:       1
cells:      1

How can I fix it?

Best,
Zac45

--
Sent from: [http://osgeo-org.1560.x6.nabble.com/Grass-Users-f3884509.html](http://osgeo-org.1560.x6.nabble.com/Grass-Users-f3884509.html)
_______________________________________________
grass-user mailing list
[grass-user@lists.osgeo.org](mailto:grass-user@lists.osgeo.org)
[https://lists.osgeo.org/mailman/listinfo/grass-user](https://lists.osgeo.org/mailman/listinfo/grass-user)

-- 
Micha Silver
Ben Gurion Univ.
Sde Boker, Remote Sensing Lab
cell: +972-523-665918
[https://orcid.org/0000-0002-1128-1325](https://orcid.org/0000-0002-1128-1325)

-- 
Micha Silver
Ben Gurion Univ.
Sde Boker, Remote Sensing Lab
cell: +972-523-665918
[https://orcid.org/0000-0002-1128-1325](https://orcid.org/0000-0002-1128-1325)
5
···

On 03/07/2020 12:33, 李泽浩 wrote:

Thanks for your advice! But I fail to run the " grass -c " code in the GRASS console. Is it should be run elsewhere?

(Keeping the thread on the list)

Sorry, you need to run the grass -c command outside of grass, at the regular command prompt (OSGeo2W shell if you installed from OSGeo4W)

Micha Silver <tsvibar@gmail.com> 于2020年7月3日周五 下午5:07写道：

On 03/07/2020 11:53, 李泽浩 wrote:

Hi Micha,

Thanks for your reply! Here is the output from gdalinfo:
This DEM is projected from WGS84 to CGCS 2000 in ArcMap first and then imported in GRASS.

gdalinfo C:\Users\zhangtong\Desktop\Zehao_DEM.tif
Driver: GTiff/GeoTIFF
Files: C:\Users\zhangtong\Desktop\Zehao_DEM.tif
Size is 3353, 1748
Coordinate System is:
PROJCS[“CGCS2000_3_Degree_GK_CM_120E”,
GEOGCS[“GCS_China_Geodetic_Coordinate_System_2000”,
DATUM[“China_2000”,
SPHEROID[“CGCS2000”,6378137,298.257222101]],
PRIMEM[“Greenwich”,0],
UNIT[“degree”,0.0174532925199433]],
PROJECTION[“Transverse_Mercator”],
PARAMETER[“latitude_of_origin”,0],
PARAMETER[“central_meridian”,120],
PARAMETER[“scale_factor”,1],
PARAMETER[“false_easting”,500000],
PARAMETER[“false_northing”,0],
UNIT[“metre”,1,
AUTHORITY[“EPSG”,“9001”]]]
Origin = (118.670833333333334,42.996666666666670)
Pixel Size = (0.000833333333333,-0.000833333333333)
Metadata:
AREA_OR_POINT=Area
DataType=Generic
Image Structure Metadata:
INTERLEAVE=BAND
Corner Coordinates:
Upper Left ( 118.6708333, 42.9966667) (115d30’50.80"E, 0d 0’ 1.40"N)
Lower Left ( 118.6708333, 41.5400000) (115d30’50.80"E, 0d 0’ 1.35"N)
Upper Right ( 121.4650000, 42.9966667) (115d30’50.89"E, 0d 0’ 1.40"N)
Lower Right ( 121.4650000, 41.5400000) (115d30’50.89"E, 0d 0’ 1.35"N)
Center ( 120.0679167, 42.2683333) (115d30’50.84"E, 0d 0’ 1.37"N)
Band 1 Block=128x128 Type=Int16, ColorInterp=Gray
NoData Value=32767

OK, that looks good.

Now you can create a new LOCATION for your GRASS data using that DEM projection information as follows:
(I’ll assume you want your GRASS database under: C:\Users\zhangtong\grassdata)

grass -c C:\Users\zhangtong\Desktop\Zehao_DEM.tif -e C:\Users\zhangtong\grassdata\CGCS2000\PERMANENT

THis command creates a new LOCATION based on the DEM coordinate system, then exits (-e option).

Now start GRASS in that new location and you should be able to import your DEM without problem:

grass C:\Users\zhangtong\grassdata\CGCS2000\PERMANENT

and then at the GRASS command prompt:

r.import C:\Users\zhangtong\Desktop\Zehao_DEM.tif output=zehao_dem

g.region -ap rast=zehao_dem

Zac

Micha Silver <tsvibar@gmail.com> 于2020年7月3日周五 下午4:43写道：

On 02/07/2020 20:58, Zac45 wrote:

Hi,

I am quite new to GRASS and this is my first post, looking for some help
here!

Welcome

I am now processing the dataset under *CGCS2000 / 3-degree Gauss-Kruger CM
120E*. But the dataset could not be recognised by GRASS when I trying to
import the DEM data.  The warning message kept poping up:

Can you show the CRS of your original DEM before import into GRASS. What’s the output from:

gdalinfo <your_original_DEM>

?

WARNING: Datum <China_2000> not recognised by GRASS and no parameters found

And the output from g.region -p is:

projection: 99 (CGCS2000 / 3-degree Gauss-Kruger CM 120E)
zone:       0
datum:      ** unknown (default: WGS84) **
ellipsoid:  grs80
north:      1
south:      0
west:       0
east:       1
nsres:      1
ewres:      1
rows:       1​
cols:       1
cells:      1

How can I fix it?

Best,
Zac45

--
Sent from: [http://osgeo-org.1560.x6.nabble.com/Grass-Users-f3884509.html](http://osgeo-org.1560.x6.nabble.com/Grass-Users-f3884509.html)
_______________________________________________
grass-user mailing list
[grass-user@lists.osgeo.org](mailto:grass-user@lists.osgeo.org)
[https://lists.osgeo.org/mailman/listinfo/grass-user](https://lists.osgeo.org/mailman/listinfo/grass-user)

-- 
Micha Silver
Ben Gurion Univ.
Sde Boker, Remote Sensing Lab
cell: +972-523-665918
[https://orcid.org/0000-0002-1128-1325](https://orcid.org/0000-0002-1128-1325)

-- 
Micha Silver
Ben Gurion Univ.
Sde Boker, Remote Sensing Lab
cell: +972-523-665918
[https://orcid.org/0000-0002-1128-1325](https://orcid.org/0000-0002-1128-1325)

-- 
Micha Silver
Ben Gurion Univ.
Sde Boker, Remote Sensing Lab
cell: +972-523-665918
[https://orcid.org/0000-0002-1128-1325](https://orcid.org/0000-0002-1128-1325)