[CF-metadata] How to define time coordinate in GPS?

From: Timothy Patterson <Timothy.Patterson>
Date: Wed, 20 May 2015 19:47:07 +0200

>From my (perhaps naive!) viewpoint, it seems the convention is trying to use a single "time" variable to encode two different concepts; the simple "elapsed time" since a given time-zero, monotonically increasing without discontinuities, in line with all other measurement variables like distances, temperatures, etc.); and an encoded "look-up-table" or "date" into which leap second discontinuities are inserted at random junctures and which may not even be defined outside certain boundaries.

I expect that any request to define, say, a temperature variable in this way - sometimes in units of Kelvin and sometimes in a different measurement system which jumped certain temperature values - would be quickly dismissed, but the current proposals for the time variable all seem to be advocating this approach instead of perhaps reserving "time" for storing the actual count of seconds, analogous to all other CF coordinate measurements, and introducing a separate "date" variable for those who want to encode whatever discontinuous, non-linear date system they choose.

I should note that this proposal might not be fully backwards compatible (i.e. it's probably entirely incompatible).

Regards,

Tim

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Received on Wed May 20 2015 - 11:47:07 BST