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John, Thank you for your help. You're absolutely right. The key problem was that at least one of the dataset variables (like Time in [1]) should have the "coordinate" attribute. I'm sorry that I wasn't careful in making the output that conforms to CF-convention. -- Joe On Thu, Jan 29, 2009 at 5:30 PM, John Caron <address@hidden> wrote: > Hi Kent: > > Yes, IDV can handle 2D lat/lons. > > In looking at dataset #2, in order to be CF-compliant, since you have 2D > auxiliary coordinate > variables, you need to add to each data variable: > > :coordinates = "lat lon"; > > its also better not to use "lat", "lon" as the dimension names, although that > is optional. > > In looking at dataset #1, we are picking up the 2d variables, as well as the > 3D variables on > pressStd vertical level. We would pick up the 3D variables on H2OPressureLev > if the variable > pressH2O was renamed H2OPressureLev and so was a coordinate variable. We pick > up these because the > variable Time has > > :coordinates = "lat lon"; > > We then use that for any other data variable. Technically, you should put > that attribute on all data > variables. > > Ill be out of town for a week, so may not be able to follow up on this until > then.s > John > > > MuQun Yang wrote: >> Hi John, >> >> How are you? We've gotten more adventures with IDV to display some files >> with OPeNDAP. The question basically boils down to if IDV can display 2D >> lat/long grid file. If not, what's your plan for that? This will be >> common for different projection grid files. See the details below. >> >> Thank you very much! >> >> Kent >> >> ------------------- from Joe Lee ----- >> >> I'm trying to visualize 2 files below with IDV: >> >> [1] >> http://hdfdap.hdfgroup.uiuc.edu:8080/cgi-bin/nph-dods/AIRS.2008.04.16.201.L2.RetStd.v5.2.2.0.G08109135217.hdf >> >> >> [2] >> http://hdfdap.hdfgroup.uiuc.edu:8080/cgi-bin/nph-dods/MYD09A1.A2002185.h00v08.005.2007175015530.hdf >> >> >> [1] is a swath file and [2] is a grid file with sinusoidal projection. >> Both have 2-D lat/long dimension variable. >> >> In short, I could display [2] but not [1]. Thus, I got a few questions >> about the IDV and the CF-convention. >> I can see the main difference between the two is the existence of Time >> dimension variable. >> >> Can't IDV display 2D lat/lon Grid without time dimension? >> If not, does IDV always require a Time dimension variable to display >> Swath data properly? >> >> To assess the problem more carefully, you may want to view DAS/DDS >> outputs of the data files using the following page: >> >> http://hdfdap.hdfgroup.uiuc.edu:8080/hdf4.html >> >> >> Regards, >> >> -- Joe >> >> >> >> > >