Michael, Use a unit of "count" for anything that is a dimensionless count. You will need either Udunits-1, or Udunits-2 version 2.1.18 or greater.
--Dave On Tue, Aug 20, 2013 at 1:41 PM, Carlomusto, Michael <[email protected]> wrote: > Good day. > > As a data producer I am seeking a resolution on the use of units="1" for > dimensionless quantities. > > Page 10 of CF Metadata Conventions version 1.6 states: > > "Units are not required for dimensionless quantities. A variable with no > units attribute is assumed to be dimensionless. However, a units attribute > specifying a dimensionless unit may optionally be included. The Udunits > package defines a few dimensionless units, such as percent, but is lacking > commonly used units such as ppm (parts per million). This convention does not > support the addition of new dimensionless units that are not udunits > compatible. The conforming unit for quantities that represent fractions, or > parts of a whole, is "1"." > > This clearly states that units="1" should be used for fractions or parts of a > whole. > > However, in the standard name table, units="1" is used for dimensionless > quantities that are not fractions. > See for example, land_binary_mask or sea_ice_classification. Is units="1" > valid for dimensionless quantities that are not fractions? Or is units="1" > simply used as the default for all standard names that are dimensionless? > > What units if any should be used for a variable named > "number_of_cloud_pixels" in a dataset containing a satellite image of the > earth? > > Thank you. > > > Michael Carlomusto > [email protected] > Harris Corp. > GOES-R Ground System > Melbourne, FL, USA > +1-321-309-7905 > _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
