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[netCDF #EVL-272024]: Standard Coordinate Transforms to Geo-locating gridded data



In the file you sent you put 2D lat/lon, which are all zero. you can do that if 
you want (not the zeroes), but another way is to put the 1D coordinate 
variables xc and yc. look at the grib file i sent you in toolsUI:

http://www.unidata.ucar.edu/software/netcdf-java/v4.2/webstart/netCDFtools.jnlp


> Hi John,
> 
> Thanks for the reply and clarification.
> 
> I have put the two files with xc and yc coordinate variables.
> 
> WithLonLan_W_XX-EUMETSAT-Darmstadt,VIS+IR+IMAGERY,MSG1+SEVIRI_C_EUMG_20101111131509.nc
> 
> WithLonLan_W_XX-EUMETSAT-Darmstadt,VIS+IR+IMAGERY,MSG2+SEVIRI_C_EUMG_20100927130009.nc
> 
> Can you please check as part of DEBUG where things are wrong? Thanks.
> 
> As of now, so what I understand is that xc and yx coordinate variables are 
> required. Putting the header information is not enough.
> 
> With these files with xc and yc coordinate variables, I am not clear how to 
> view MSGnavigation projection in IDV?
> 
> Thanks and cheers,
> Jags
> 
> -----Original Message-----
> From: Unidata netCDF Java Support [mailto:address@hidden]
> Sent: Wednesday, November 02, 2011 3:31 PM
> To: Peter Miu
> Cc: address@hidden; Peter Miu; Michael Schick; Anastasia Andres; Jagmohan 
> Khulbe
> Subject: [netCDF #EVL-272024]: Standard Coordinate Transforms to Geo-locating 
> gridded data
> 
> Hi Peter:
> 
> The problem is that you need to add xc and yc coordinate variables, which are 
> used in the MSG projection. Im attaching a grib file with this projection. 
> open in toolsui and look at those coordinates to see how its done.
> 
> im still downloading the second file from ftp.
> 
> John
> 
> > Hi John,
> >
> > Sorry for the delay, we had two EUMETSAT holidays this week.
> >
> > You can find example files under the following FTP server:
> >
> > >> ftp://ftp.eumetsat.int/pub/EUM/out/USD/Unidata_test_files
> >
> > Can you let me know when you have downloaded them so that these files can 
> > be deleted.
> >
> > Thanks and Regards,
> >
> > Pete.
> >
> > -----Original Message-----
> > From: Unidata netCDF Java Support
> > [mailto:address@hidden]
> > Sent: Saturday, October 29, 2011 12:50 AM
> > To: Peter Miu
> > Cc: Peter Miu; Michael Schick; Anastasia Andres; Jagmohan Khulbe
> > Subject: [netCDF #EVL-272024]: Standard Coordinate Transforms to
> > Geo-locating gridded data
> >
> > Hi Peter:
> >
> > Do you have a file with this in it? its usually faster for me to debug 
> > these problems with a real file.
> >
> > Put it on ftp or http if its large. thanks
> >
> > John
> >
> > > Hi,
> > >
> > > We are investigating using the standard coordinate transforms to
> > > geo-locate the data in our SEVIRI MSG15 data sets.  If we are able
> > > to do this, then we can reduce the size of the MSG15 NetCDF files by 
> > > removing the lat and lon arrays.
> > >
> > > Please take a look at the CDL of the NetCDF definition we have 
> > > implemented.
> > > The following is specified to provide the Unidata tools e.g. IDV,
> > > information On how to geo-locating the data.
> > >
> > > char Space_View_Perspective_or_Orthographic;
> > > :_CoordinateAxisTypes = "GeoX GeoY"; :longitude_of_projection_origin
> > > = 0.0; // double :latitude_of_projection_origin = 0.0; // double
> > > :height_from_earth_center = 4.2163970098E7; // double
> > > :semi_major_axis = 6378140.0; // double :grid_mapping_name =
> > > "MSGnavigation"; :_CoordinateTransformType = "Projection";
> > > :earth_shape = "Earth oblate spheroid with axes specified by
> > > producer in m"; :scale_y = -35785.830098; // double :scale_x =
> > > 35785.830098; // double :semi_minor_axis = 6356755.5; // double
> > >
> > > This does not work so can you provide us with some information on how to 
> > > specify these coordinate transforms correctly.
> > > We can upload an example NetCDF file with this defined to your server for 
> > > you to used if it would help with the analysis.
> > >
> > > Regards,
> > >
> > > Peter Miu
> > > Data Services Operations Engineer
> > > EUMETSAT
> > > EUMETSAT Allee 1
> > > 64295 Darmstadt
> > > Germany
> > >
> > > Tel: +49 6151 807 3290
> > > URL: http://archive.eumetsat.int
> > >
> > >
> > >
> >
> >
> > Ticket Details
> > ===================
> > Ticket ID: EVL-272024
> > Department: Support netCDF Java
> > Priority: Normal
> > Status: Open
> >
> >
> 
> 
> Ticket Details
> ===================
> Ticket ID: EVL-272024
> Department: Support netCDF Java
> Priority: Normal
> Status: Open
> 


Ticket Details
===================
Ticket ID: EVL-272024
Department: Support netCDF Java
Priority: Normal
Status: Open