[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[IDV #SUF-224604]: netcdf file formatting issue

> I uploaded two files.  The other was called lma_Redoubt_20090323_1230_ev.nc
> 
> This one has a 200x200 element array, representing pixels on a map, and the 
> value is the number of events in the pixel.  I have not yet gone to the 
> trouble to extract the lat/lon coordinates for each array element.
> 
> However, the data from the file you looked at is data and contains "real 
> variables."  My data is the lat/lon/time of radiation events by lightning.  I 
> want to overlay their location onto other data my colleagues have (who use 
> IDV). If you wanted, I could just make another dummy variable with the same 
> length as the lat/lon and fill it with ones, but I don't see the point in 
> that.  Alternatively, you could consider the time variable the "real 
> variable."
> 
> Sonja


Sonja,
    The second file is not a good netCDF file too. Only a variable and two 
dimensions in this file. To construct a good netCDF file, you need to have 
dimensions and associated variables, and projection, "real variables", and 
global attributes. Each variable should has its own attribute, such as unit, 
standard name, coordinate axises, and  so on.... In general, the structure of 
lat lon projection gridded dataset is the simplest.
    Here is the web page for more details information: http://cfconventions.org/


Yuan

> ________________________________________
> From: Unidata IDV Support [address@hidden]
> Sent: Tuesday, May 06, 2014 5:28 PM
> To: Behnke, Sonja
> Cc: address@hidden
> Subject: [IDV #SUF-224604]: netcdf file formatting issue
> 
> > Hello,
> >
> > Thank you.  I have uploaded the two netcdf files I discuss below.
> >
> > Sonja
> 
> 
> I am checking the dataset named lma_Redoubt_20090323_1230.nc, is this the one 
> you uploaded? The problem is that there is no
> grided variable in this file, only lat/lon/time coordinate variables. You 
> need to add at least one real variable, such as temperature or pressure, 
> based on these coordinate variables.
> 
> 
> 
> Yuan
> > ________________________________________
> > From: Unidata IDV Support [address@hidden]
> > Sent: Friday, May 02, 2014 7:59 PM
> > To: Behnke, Sonja
> > Cc: address@hidden
> > Subject: [IDV #SUF-224604]: netcdf file formatting issue
> >
> > Sonja,
> >
> > Can you upload your data here and let us know when it is uploaded?
> >
> > http://motherlode.ucar.edu/repository/alias/idvupload
> >
> > Best,
> >
> > Unidata IDV Support
> >
> >
> > > Hello,
> > >
> > > I am trying to collaborate with a colleague who uses IDV to visualize her 
> > > modeling results.  I have my own data that I would like to overlay on 
> > > hers using IDV.  I use IDL, and I am trying to export my data into netCDF 
> > > format.  I know how to do this, but I don't know what IDV is expecting of 
> > > me.  Let me describe my data:
> > >
> > > At simplest I have three arrays: time, latitude and longitude.
> > >
> > > time[i] = time of event
> > > latitude[i] = latitude of event
> > > longitude[i] = longitude of event
> > >
> > > I wrote a program in IDL to make a netcdf file of three variables: time, 
> > > latitude, and longitude.  I know I did this correctly because I reread 
> > > the file back in to IDL and was able to extract my arrays.
> > >
> > > But, IDV doesn't know what to do with my data.  It complains that I don't 
> > > have any "gridded" data in my file.  So, I took my data in IDL and made a 
> > > 200x200 element array of the density of my events with respect to lat and 
> > > lon.  So each element of the array is a pixel on a map, and the value 
> > > represents how many events were in that pixel. I saved that 200x200 array 
> > > in a netcdf file, but alas, IDV doesn't get it.
> > >
> > > So, I realize I don't know what IDV is expecting here with my data, but I 
> > > would like to format my data so that it understands it and I could use 
> > > IDV to plot it on a map.
> > >
> > > Can you help with this?
> > >
> > > Thank you,
> > >
> > > Sonja Behnke
> > >
> >
> >
> > Ticket Details
> > ===================
> > Ticket ID: SUF-224604
> > Department: Support IDV
> > Priority: Normal
> > Status: Open
> >
> >
> 
> 
> Ticket Details
> ===================
> Ticket ID: SUF-224604
> Department: Support IDV
> Priority: Normal
> Status: Open
> 
> 


Ticket Details
===================
Ticket ID: SUF-224604
Department: Support IDV
Priority: Normal
Status: Closed