[IDV #RTU-584517]: Example file with IDV gridded data issue

> Yuan,
> 
> Thanks for the response.
> 
> So the problem is not that we have the 3rd dimension, but rather the problem 
> is that it does not have a CF-compliant name associated with it - right?  
> Then other than using a kluged name, there is no way to get these files to 
> work with IDV?

you are right. 
> 
> That could be an obstacle for us.  Since we are generating an official 
> dataset that will be going into a NASA archive, we probably don't want to use 
> a name that would be misleading, such as "ensemble".  I gather 
> characteristics of satellite data may not be too well supported yet, since 
> pass direction is a pretty fundamental concept.
> 

I would suggest that you create different dataset with the attribute to define 
the direction, this will make it easier. I also like to see what the netcdf 
group will recommend.


Yuan

> We will be interested to hear what the netcdf folks have to say.  I assume 
> there must be a procedure to suggest new terms to be adopted into the CF 
> nomenclature, right?  Is that worth pursuing or is the timeframe involved too 
> lengthy?
> 
> thanks
> 
> Ken
> 
> 
> 
> 
> On Oct 3, 2011, at 2:32 PM, Unidata IDV Support wrote:
> 
> >> IDV Folks,
> >>
> >> We are are the verge of converting several existing datasets from a 
> >> previous proprietary binary format into (hopefully) CF compliant netCDF to 
> >> make the data more accessible to the wider Earth science community.  Part 
> >> of our conversion process has been to test the new formatted data with the 
> >> various tools that support netCDF.  IDV is an obvious choice, and we ran 
> >> into a hiccup with that testing.  We have two main types of satellite data 
> >> sets across several different platforms: (1) a composite of each day's 
> >> swaths, and (2) a 3-day average of the same data.  The structure of both 
> >> data sets is nearly identical, with the exception that the daily composite 
> >> (1) has an array of "pass direction" flags, so each parameter has an 
> >> ascending and descending view.
> >>
> >> Both of these data sets (daily and 3-day) seem to be handled fine by other 
> >> tools, i.e. panoply, but we have a problem with the daily files when 
> >> attempting to read them with IDV.  IDV complains that it cannot find any 
> >> gridded data and (apparently) fails to open the file. Our best guess is 
> >> that the "pass direction" array is causing the problem, but based on our 
> >> interpretation of the documentation for both netCDF and IDV, the structure 
> >> we have created should be correct.
> >>
> >> We would like to get this resolved before starting the conversion of these 
> >> datasets at our repository - the Global Hydrology Resource Center (GHRC) - 
> >> a NASA DAAC.  We would really appreciate it if you could review the linked 
> >> files and give us a read on if we are doing something wrong or if this is 
> >> a problem for IDV.  If it is our problem, we would like to fix it before 
> >> our conversion effort.  If it is IDV's problem, then we can go ahead with 
> >> our conversion and hope it gets resolved.
> >>
> >> At the links below, is one example of both the daily composite and the 
> >> 3-day average.  We are using the Java netCDF 4 libraries to create these 
> >> files, which as we understand it generates netCDF-3 output.  A little 
> >> confusing, but that is what we understand from the documentation.
> >>
> >> Daily
> >> http://www.itsc.uah.edu/~keiser/projects/DISCOVER/netCDF/IDV_test/f13_20090101v7.nc
> >>
> >> 3-Day average
> >> http://www.itsc.uah.edu/~keiser/projects/DISCOVER/netCDF/IDV_test/f13_20090101v7_d3d.nc
> >>
> >>
> >
> > Hi Ken,
> >    I checked these two datasets, the 3-day average is looking good in the 
> > IDV. The problem with the daily dataset is indeed this additional 
> > dimension. I don't think there is CF convention to deal with this type of 
> > dimension. But you do need a variable to go with a dimension. The only 
> > possible I can think about is to cheat this dimension as Ensemble, see the 
> > attached ncml file, and this can make this dataset being recognized as grid 
> > type in the CDM and can be loaded in the IDV. I will transfer this support 
> > to netcdf-java department to ask for their help.
> >
> >
> >
> > Yuan
> >>
> >> We appreciate any guidance you can provide on this.
> >>
> >> Ken Keiser
> >> ------------------------------
> >> Information Technology and Systems Center
> >> University of Alabama in Huntsville
> >> email: address@hidden
> >> phone: 256-824-6825
> >>
> >>
> >>
> >>
> >>
> >>
> >
> >
> > Ticket Details
> > ===================
> > Ticket ID: RTU-584517
> > Department: Support netCDF Java
> > Priority: Normal
> > Status: Open<f13_20090101v7.ncml>
> 
> ------------------------------
> Information Technology and Systems Center
> University of Alabama in Huntsville
> email: address@hidden
> phone: 256-824-6825
> 
> 
> 
> 
> 


Ticket Details
===================
Ticket ID: RTU-584517
Department: Support netCDF Java
Priority: Normal
Status: Open