> Does WMS/WCS allow other than lat/lon bounding boz?
Yes, you can specify a BBOX in other coordinate systems *as well* as a
lat-lon BBOX. Therefore we need an accurate (even if it isn't
precise) BBOX in lat-lon. If in doubt, a BBOX that covers the whole
world is at least valid, even if it's not terribly helpful. (the
lat-lon BBOX is really a hint to search and visualization systems.)
> LLbb= ll: 34.57N 79.65W+ ur: 90.0N 169.6E
Yes, this is definitely an improvement over what I get from version
2.2.22 but still not right - it should cover the whole longitude range
(the latitude range looks reasonable though.)
Thanks for your help,
Jon
On Jan 26, 2008 7:37 PM, John Caron <caron@xxxxxxxxxxxxxxxx> wrote:
> Yes, i can imagine that a polar projection will give bad results for the
> lat/lon BB. We really need to replace that with a bounding polyline. Does
> WMS/WCS allow other than lat/lon bounding boz?
>
> I did check the dataset pointed to by ArcticTEP.ncml, and it had a reasonable
> bounding box:
>
> LLbb= ll: 34.57N 79.65W+ ur: 90.0N 169.6E
>
> still not great, but not empty at least. I see that you're using TDS 3.14, im
> not sure if ive fixed a bug (im testing with 4.0.11 alpha) or we are looking
> at different datasets.... Ill make a release on monday so that you can check
> against 4.0, and i'll look at your specific dataset next week.
>
>
> Jon Blower wrote:
> > 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/
> >
> >
> >
>
--
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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
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