Hi John, That's brilliant, thanks very much. Everything (nearly) now appears to work: http://lovejoy.nerc-essc.ac.uk:8080/ncWMS/mersea.html?menu=MERSEA&layer=MERSEA_ARCTIC_TOPAZ/temperature&elevation=-5&time=2008-01-24T00:00:00Z&scale=-3.055269694328308,22.592125034332277&bbox=-65.039062,18.28125,24.960938,88.59375 However, there seems to be a problem with GridCoordSystem.getLatLonBoundingBox() for this dataset (presumably because of the polar stereographic projection). This function returns a zero-sized bounding box (with minLat = maxLat). The longitude range also appears wrong. I would expect this to return a BBOX of the form (-180, minLat, 180, 90), i.e. covering the full longitude range and ranging from some minimum latitude to the North Pole. The ncml file is attached that contains your metadata corrections, in case you want to test getLatLonBoundingBox(). Cheers, Jon On Jan 22, 2008 12:25 AM, John Caron <caron@xxxxxxxxxxxxxxxx> wrote: > Hi Jon: > > 1) y coordinate is missing units attribute > 2) latitude unit should be "degrees_north", not "degrees" > 3) longitude unit should be "degrees_east", not "degrees" > 4) most of the the data variables have "_CoordinateAxes" attributes missing > the time coordinate, eg: > > :_CoordinateAxes = "longitude latitude y x "; > > should be: > > :_CoordinateAxes = "longitude latitude y x time "; > > The rule for "_CoordinateAxes" is that they have to be complete, if you are > going to use them. If > you left "_CoordinateAxes" off, then the CF-1.0 convention > > :coordinates = "longitude latitude"; > > would work, since the coordinate variables (x,y,time) would be automatically > added. > > Jon Blower wrote: > > Hi all, > > > > I'm trying to use the Java NetCDF libraries (2.2.22) to read Arctic > > ocean data over OPeNDAP. The data are in polar stereographic > > projection. However, the following short program (which works fine > > for many other datasets) returns zero Grids: > > > > NetcdfDataset nc = NetcdfDataset.openDataset(url, true, null); > > GridDataset gd = > > (GridDataset)TypedDatasetFactory.open(DataType.GRID, nc, null, null); > > System.out.println(gd.getGrids().size()); // prints out "0" > > > > The URL to the OPeNDAP site is > > http://topaz.nersc.no/thredds/dodsC/topaz/mersea-ipv2/arctic/tmipv2a-class1-be. > > The results of performing an ncdump on this URL (using toolsUI) are > > attached. toolsUI also fails to recognize any Grids in this dataset. > > > > Can anyone advise on what might be the problem here? Is the metadata > > of the dataset incorrectly specified? > > > > Thanks in advance, > > Jon > > > > > > > > ------------------------------------------------------------------------ > > > > _______________________________________________ > > netcdf-java mailing list > > netcdf-java@xxxxxxxxxxxxxxxx > > For list information or to unsubscribe, visit: > > http://www.unidata.ucar.edu/mailing_lists/ > -- -------------------------------------------------------------- Dr Jon Blower Tel: +44 118 378 5213 (direct line) Technical Director Tel: +44 118 378 8741 (ESSC) Reading e-Science Centre Fax: +44 118 378 6413 ESSC Email: jdb@xxxxxxxxxxxxxxxxxxxx University of Reading 3 Earley Gate Reading RG6 6AL, UK --------------------------------------------------------------
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ArcticTEP.ncml
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