John Graybeal wrote:
I think 'requiring a Z' and 'requiring a Z with every point' are two different things. I don't think anyone meant to argue for the latter, or they'll correct me if I'm wrong.
To take an easy case first, for surface-based measurements like ship point observations, specifying 'surface' in one place for all Z coordinates (e.g., via an attribute) seems like a reasonable approach.
You can use a scalar, "nominal" coordinate variable, like: variables; char z(z_strlen); float lon(obs); float lat(obs); double time(obs); float dataVar(obs); dataVar:coordinates = “lon lat z time”; data: z = "tropopause";