Jonathan Gregory wrote:
Dear John Usually z is useful, but I don't think we should insist on providing something which is not really useful just to fill a slot which has been mandated. Also I don't think we should confuse the z of the quantity being measured with the z of the platform which is measuring it. John C suggests people may be prompted to supply info if the CF checker or some other such device points out it is missing. That may be more effective than laying down laws, which people may ignore. (Another argument is that an effective convention such as CF should contain things which people will agree to do - albeit a bit reluctantly - as they see the value of it, but should be careful not to prescribe excessive burdens that they will ignore as they don't see the use of them.) So if a rule can be given (in terms of something that a file-checker can apply) for when a z coordinate would usefully be present, this can be made a recommendation, and the CF checker can issue a warning if the z coord is missing. It gives warnings for unsatisfied recommendations (when that can be detected) and errors for unsatisfied requirements.
Another great "pull" for encouraging data writers to include as much metadata as possible is an application that won't load the data unless that important piece of information is provided. Of course, like the CF checker the application would clearly report what is missing as a help to the data writer. Question for Don: How would IDV show an XY field that has no Z value specified? -Mike -- Mike McCann Software Engineer Monterey Bay Aquarium Research Institute 7700 Sandholdt Road Moss Landing, CA 95039-9644 Voice: 831.775.1769 Fax: 831.775.1736 http://www.mbari.org