Dear Martin I don't think that anyone has responded on the CF email list to your detailed email at the end of Jan, have they? (in the archive at: http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2012/027738.html) That is a pity and I hope that there will be other responses. Thank you for your carefully considered proposals. It might be there haven't been replies because there is a lot to consider at once! Here are my comments on some of your points:
> standard name: surface_reflectance > definition: fraction of incident > radiation<http://en.wikipedia.org/wiki/Reflection_%28physics%29> > reflected by a surface, wavelength dependent Is this different from surface_albedo, which we already have? surface_albedo could have a coordinate of radiation_wavelength to make it spectral. > standard name: probability_of_fire_occurrence > definition: probability that the observed pixel shows a burned area > unit: none (a value between 0 and 1) If I remember correctly, there is an approved proposal for burned area with a different standard name, that is going to be added to the table. > standard name: probability_of_snow_occurrence > definition: probability that the observed pixel shows snow or ice > unit: none (a value between 0 and 1) I think this would be a bit imprecise because it doesn't say exactly what "snow" means (snowfall or lying snow) and it doesn't say what the threshold is. I would suggest something more explicit such as probability_of_surface_snow_amount_above_threshold with a coordinate or scalar coordinate of surface_snow_amount (kg m-2) to specify the threshold; this could be a multivalued coordinate variable if there are several thresholds. There are other possibilities such as lwe_thickness_of_surface_snow_amount (m) - it depends what you want. Such names would be consistent in style with existing ones like number_of_days_with_air_temperature_above_threshold > standard name: probability_of_water_occurrence > definition: probability that the observed pixel shows water > unit: none (a value between 0 and 1) I am not sure what this means, to be honest. Again, it would be good to make it more precise by building a probability name from an existing (or a new) standard name for the quantity on which a threshold is set. > For the existing standard name land_cover which is a synonym of > area_type we propose to allow for external vocabularies as valids. Yes, use of external vocabularies is fine if they are standardised, available online and well-maintained. However, as you say, CF maintains its own area_type table. Therefore would it be better to introduce a new standard_name specifically for land cover types of the UN Land Cover Classification System? I presume that system has some governance arrangement of its own. If we had a different standard name for it we would avoid conflicts and overlaps. > standard name modifier: confidence_level > definition: applied to some discrete variable, denotes the probability that > the assignment of the value to the variable is correct Yes, I think that would be an appropriate use of a standard_name modifier. > standard name modifier: consistence_level > definition: applied to some variable, with relation to some other > variable, denotes level of consistency within the dataset I am unclear about this, since it is not a quantity I have encountered before. Does it have a precise definition? > standard name modifier: source_flag > definition: applied to some variable, denotes information source > used to derive the value Yes, I think this too could be a standard_name modifier, but I would suggest "source", since there is an attribute of that name, with a similar intent. Logically variables with a source modifier would be strings, but as usual they could be encoded as flags with flag_values and flag_meanings. Additions to the list of standard_name modifiers in the CF standard Appendix C is a modification to the CF convention, not the standard name table. To propose to modify the CF convention, you should open a new trac ticket http://cf-pcmdi.llnl.gov/trac/query?status=new&status=assigned&status=reopened&status=closed&order=id&desc=1 and specify in the ticket the modification to the text of the standard. There is a template for trac tickets to modify the convention. If you haven't got a CF trac account, I believe Jeff Painter could help (paint...@llnl.gov). Best wishes Jonathan _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata