[CF-metadata] stations and trajectories (the OTS standard)

From: John Caron <caron>
Date: Mon, 20 Jun 2005 14:39:28 -0600

Jonathan Gregory wrote:

>Dear Nan
>
>
>
>>>But instead they could be CF-compliant by dimensioning
>>>the data variable as (time,depth) and giving it a coordinates
>>>attribute to point to auxiliary coordinate variables of lat(time)
>>>and lon(time).... These are what CF calls "scalar coordinate
>>>variables" and they avoid introducing a size-one dimension
>>>just to attach coordinate info.
>>>
>>>
>>Maybe I didn't think this through well enough, or I completely missed one of
>>the basic CF concepts. I somehow missed that CF files should "avoid
>>introducing a size-one dimension just to attach coordinate info" and thought
>>that 4 dimensions was a reasonable way to go, as it gives you the overall
>>size of the dataset in one query.
>>For mooring data, this seems to make perfect sense.
>>
>>
>
>Yes, I agree. I am not saying that there's anything wrong with (time,lat,lon)
>with lat=lon=1. It does make sense for a timeseries at a fixed point. Scalar
>coordinate variables are offered as an alternative "convenience feature", not
>as a recommendation, and actually you might be cautious of using them if your
>analysis software doesn't recognise them.
>
>My point was that if auxiliary coordinate variables lat(time) and lon(time)
>are used for drifters, your software must be able to process the coordinates
>attribute; hence in that case you *could* use scalar coordinate variables for
>lat and lon if you wanted too, as they are auxiliary coordinate variables too.
>If you did that, the two kinds of timeseries (fixed and floating) would have
>the same kind of dimensions.
>
>
I agree with Jonathon about the use of the coordinates attribute for
your datasets, especially if you need to store multiple buoys in the
same file, or if you had drifting buoys.
Received on Mon Jun 20 2005 - 14:39:28 BST