Parameter files

Parameter files contain the coefficients that a calibrator uses. For example, a simple linear regression scheme (e.g. a + b *x) contains two parameters. A single instance of a vector with one value of a and b is called parameter set. A parameter file contains parameter sets for one or more positions and one or more leadtimes. It is up to each calibrator to define the behaviour.

Text format

The text format is space delimited with one parameter set on each line.

The file contains a header row that describes each column. They can be in any order and the following keywords are recognized:

• lat: Latitude in degrees (north is positive)
• lon: Longitude in degrees (west is positive)
• time: Leadtime in hours
• param<N>: Parameter value (numbered 1 and up)

A linear regression parameter file might look like this:

lat lon param1 param2
60  10  0.1    0.9
61  5   0.2    1.1

NetCDF format

For large parameter sets, the NetCDF format is faster.