fields not appearing for display

[kbedka1]

I have a NetCDF file that I'm trying to display in Mc-V on the SSEC ftp server at pub/incoming/A2016210.2000.nc There are a lot of parameters in this file but only a handful are available for display, see attached screenshot. Any idea what could be causing this issue?

[bobc]

Hi Kris -

I picked up your file, and there looks to be differences in how the dimensions of the different fields/variables are defined in the file. The fields that list in the Field Selector specifically have 'time', 'nlines', and 'npixels' listed for the variables. For example (from an ncdump):

Code: Select all

    short visible_reflectance(time=1, nlines=868, npixels=1540);
      :long_name = "Visible Reflectance Image";
      :valid_range = 1US, 15000US; // short
      :units = "percent";
      :_FillValue = -1US; // short
      :scale_factor = 0.01f; // float
      :coordinates = "longitude latitude time";
      :_Unsigned = "true";
      :_ChunkSizes = 1, 868, 1540; // int

For the fields that don't list, the dimension names aren't explicitly written out, just the numerical values for them. For example:

Code: Select all

    short ot_probability(1, 868, 1540);
      :long_name = "OT Probability";
      :units = "unitless";
      :coordinates = "longitude latitude time";
      :_FillValue = 0US; // short
      :scale_factor = 0.01f; // float
      :_Unsigned = "true";
      :_ChunkSizes = 1, 50, 50; // int

From passing this file through NetCDF ToolsUI it looks like if the dimension names aren't listed, they are treated as 'anonymous' and McV doesn't know how to work with this. I wrote up McV Inquiry 2396 to investigate if this is just an issue with the files (maybe these dimension names are required to be defined?) or if this is an issue with McV where it should be able to work with these 'anonymous' dimension.

I haven't tested this yet, but if you have a specific variable/field you want to work with that isn't listed in McV, you can probably create a NcML wrapper file to define thes dimension names for that variable/field. If you want, I can give this a try if you let me know what variable/field you are interested in.

Thanks -
Bob Carp

[bobc]

Hi Kris -

I'm not sure if this is still relevant to your current work, but I took another look at Inquiry 2396 and put together a NcML file that explicitly defines the shape (set of dimensions) of each variable that has anonymous dimensions. As it is currently set up, you would just have to place the attached NcML file in the same directory of your NetCDF files and change the filename after location= in the 2nd line of the file to get things working for individual files. If you wanted to keep this NcML file in a different directory than the NetCDF files, you can specify the full path to the file after location= as well. Once this NcML file is loaded into the Field Selector, all of the variables should be available to display.

Please let me know if you have any questions about this.

Thanks -
Bob