Dear John > time_from_device: time reported by some device (data source)
Somehow this seems a bit unsatisfying to me. It doesn't really suggest that this time might not be true time. Given your definition, why not call it reported_time, or maybe indicated_time. Your original sensor_time has the different advantage that we have another stdname mentioning "sensor". > (I just changed the form of this name so that it is collocated > with the other time variables) I sympathise, but I think we should deal with that problem by having better tools for displaying and searching the table. There are many groups of related stdnames that are not adjacent in alphabetical order. > The following three can each have an attribute pointing to the > variable that determines the time sequence; for example, the attribute > could name another source of time values, and the current year is > established by those values. The units in all 3 are the same as the > units for time. > > time_since_start_of_year: amount of time elapsed since the current > year began > time_since_start_of_day: amount of time elapsed since the current day > began If you have other time variables which indicate the day and year, these would be redundant, wouldn't they? You can deduce them from the time variable, especially if it is in days since midnight on 1 Jan in some year. I'm always worried about redundancy meaning possible inconsistency. > time_since_start_of_mission: amount of time elapsed since the current > mission began If the time variable has the start of the mission as the reference in its units, it serves both purposes. That would be an informal extra convention. To deduce the time since the start of the mission from a time variable, you need to know when the mission started. So perhaps you could store a variable for mission_start_time. That would be analogous to forecast_reference_time, and would be scalar. I feel more comfortable with that than with time since start of mission, because the latter is an array with a constant offset from the actual time, so again this would be redundant. However if the actual time itself is not stored in a variable, the time since the start of the mission would be independent, and I'd be happy with it. As a slightly snappier but I think equally clear name, what about mission_elapsed_time, which is what NASA call it? Best wishes Jonathan _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
