[GRASS-user] importing raster from a linear projection into current location

[Markus Metz]

On Fri, Mar 1, 2013 at 11:34 PM, Seb <spluque at gmail.com> wrote:
> On Fri, 1 Mar 2013 23:16:54 +0100,
> Markus Metz <markus.metz.giswork at gmail.com> wrote:
>
>> On Fri, Mar 1, 2013 at 11:06 PM, Sebastian P. Luque <spluque at gmail.com> wrote:
>>> On Fri, 1 Mar 2013 22:42:56 +0100,
>>> Markus Neteler <neteler at osgeo.org> wrote:
>
>>>> On Fri, Mar 1, 2013 at 9:53 PM, Seb <spluque at gmail.com> wrote:
>>>>> Hi,
>
>>>>> I am trying to import a series of rasters (HDF) in a linear
>>>>> projection, i.e. without any projection information, where x and y
>>>>> are simple indexes; gdalinfo shows:
>
>>>> Could you say a bit more about the HDF files? The xy output is
>>>> probably right but GCPs may be in the file itself (so gdalwarp is
>>>> needed or the like).
>
>>> This file was produced with WIM/WAM (wimsoft.com), and the full
>>> output of gdalinfo is:
>
>>> $ gdalinfo chl_48_200.hdf Driver: HDF4Image/HDF4 Dataset Files:
>>> chl_48_200.hdf Size is 1572, 1114 Coordinate System is `' Metadata:
>>> Base=10 Intercept=-2 Map Projection=WIM Linear Scaling=Logarithmic
>>> Slope=0.015 WIM Color Range=0, 255 WIM Color Stretch=48, 200 WIM
>>> Linear Coeffs=45, 0.012723, -40, -0.008977 Corner Coordinates: Upper
>>> Left ( 0.0, 0.0) Lower Left ( 0.0, 1114.0) Upper Right ( 1572.0, 0.0)
>>> Lower Right ( 1572.0, 1114.0) Center ( 786.0, 557.0) Band 1
>>> Block=1572x636 Type=Byte, ColorInterp=Gray
>
>>> The relevant information is in the "WIM Linear Coeffs" line, where
>>> 45, -40 are the coordinates of the upper right corner of the map, and
>>> 0.012723, -0.008977 are the lon, lat resolution.
>
>> It seems that you need to override the projection check with r.in.gdal
>> -o. After that, you need to fix the raster metadata with r.region.
>
> If I do that I get:
>
> r.in.gdal -o input=chl_48_200.hdf output=chl_48_200
> Over-riding projection check
> G_set_window(): Illegal latitude for North

Oops. I forgot, you also need the -l flag for r.in.gdal to force
Lat/Lon maps to fit into geographic coordinates (90N,S; 180E,W). After
that you need to run r.region, otherwise the raster is not usable.

Markus M