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− | {{WCS Glossary
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− | |TermDesc=Standard how to organize your NetCDF files.
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− | |Links=[http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.4/cf-conventions.html CF 1.4]
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− | }}
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− | NetCDF file format contains four kinds of information:
| + | This spelling is obsolete. Please go to [[CF-netCDF]] |
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− | * Global attributes
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− | ** Simple name=value pairs
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− | * Dimensions
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− | ** Only declares the length of the dimension
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− | ** Contains no dimension data.
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− | * Variables
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− | ** Array data with any number of dimensions.
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− | ** Zero dimensions meaning scalar data.
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− | * Variable Attributes:
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− | ** Simple name=value pairs associated to a variable.
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− | While these are enough to describe any data, it's not easy to interpret what the data actually means. What is self-evident for humans is difficult for a computer program to reason. If you have a NetCDF viewer, it should be possible just open the file and display the data on a geographic map. But making a program that can automatically get the geographic dimensions from a NC file, is very difficult.
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− | Conventions come to rescue. CF-1.0 Standardizes many things:
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− | * Standard name: what is the measure data about
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− | * Units
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− | * How to tell, that a variable is one of the following:
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− | ** Data Variable, containing real data.
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− | ** Dimension Coordinate Variable, containing dimension coordinates.
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− | ** Dimension Bounds Variable, containing lower and upper bounds of a dimension coordinate.
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− | * Projection
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− | With this part standardized, your program can list the data variables for you and tell you exactly what you can filter by.
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− | Links:
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− | CF 1.0 - [http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.4/cf-conventions.html 1.4] contain conventions for cube data.
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− | [https://cf-pcmdi.llnl.gov/trac/wiki/PointObservationConventions Unofficial CF-1.5] contains point data encoding. '''Expired certificate''', add security exception. | |
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− | [http://www.cfconventions.org/ CF Conventions]
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− | [http://www.unidata.ucar.edu/software/netcdf/conventions.html NetCDF Conventions]
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− | [http://www.unidata.ucar.edu/software/netcdf/ Unidata NetCDF documentation]
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− | [http://wiki.esipfed.org/index.php/Creating_NetCDF_CF_Files Creating NetCDF CF Files]
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