Recommendation:
The valid range for each variable in an Earth Science data product should put useful constraints on the data.
Recommendation Details:
Declaring valid range of a variable's data according to the CF metadata conventions is one of the DIWG recommendations [insert ref. here]. The data value range can be specified either by two CF attributes, valid_min and valid_max , or with the CF attribute valid_range. Both approaches are allowed but not for the same variable.
The range values declared using these attributes are dependent on the type of data and their intended application but should be chosen as meaningful constraints of all the possible data values. The CF metadata conventions require that any data value representing missing data or the variable's fill value must be excluded from the valid data range.
Generic range values are discouraged unless the actual data range is poorly understood. For example, we discourage using the theoretical limits of a specific computer data type, such as floating-point single or double precision, as the valid range.
Overview
Content Tools