Repository entries that are recognized as grids (i.e, can be read by the
netCDF-Java Common Data Model (CDM) grid reader (e.g. netCDF, GRIB, GrADS))
provide an option for creating subsets of the grids that can be downloaded
or stored in the repository. From the
The Grid Subset form allows you to subset the grid by region, time and variable
and will output the result to a CF compliant netCDF file.
At the bottom of the subset form is a URL that is configured with any of the form setttings. You can use this to programattically access the grid, e.g., usin cURL.
- Horizontal Stride
Sample every Nth grid point where N is the stride value
- Subset Spatially
Enter the spatial bounds for the subset. Click on the link to pop up a map where you can select the bounds using Shift-Drag. The link removes the selection.
- Time Range
Set the time range for the subset. Default is all times.
- Add Lat/Lon Variables
For the grid to be CF compliant,
the latitude and longitude values at each point must be included
in the file. If the grid is projected, the grid projection definition is
also stored in the file, which is enough for some software packages.
- Select a folder to publish the results to
If you are logged in and have permission to add files to the repository, you can optionally add the file to the repository. Specify the Folder location and a name for the file.
- Select Variables
Select the variables that you wish to include
in the output file.