Thanks again, Seth, now it's clear.
Cheers, Andreas.
> If your intervals are contiguous, time_bounds[i,1] should equal
> time_bounds[i+1,0] (See the beginning of section 7.1 in the CF spec.) So for
> January 2013, you should set the endpoint to 2013-02-01 00:00:00.
>
> (The resulting potential for confusion is why I think it's best practice to put
> the time coordinate at the midpoint of the interval rather than either end.)
>
> There's been some discussion of time resolution on this list, but nothing
> that's made it into the spec.
>
> Cheers,
>
> --Seth
>
>
> On Fri, 15 Mar 2013 23:12:27 +0100
> Andreas Hilboll <lists at hilboll.de> wrote:
>> Seth, thanks for this nice walkthrough! I still have one question,
>> regarding 3):
>>
>> for Jan 2013, I would chose 2013-01-01 00:00:00 as the start point, but
>> what about the end point?
>>
>> - 2013-01-31 23:59:59
>> - 2013-01-31 00:00:00
>> - ...
>>
>> Is it possible to somehow set the time 'resolution'
>>
>> Cheers, Andreas.
>>
>>
>>> 1) Set the time values to the midpoint of the time interval.*
>>>
>>> 2) Set a "cell_methods" attribute on the data variable with a
>>> value of "time: mean (interval: 1 month)".
>>>
>>> 3) Create a time_bounds variable with dimensions (time,2)
>>> whose values are the start and end points of each time interval.
>>>
>>> 4) Set a "bounds" attribute on the time coordinate variable
>>> equal to the name of your time_bounds variable.
>>>
>>> *CF allows you to put the time coordinate anywhere in the
>>> interval, but in my experience at the midpoint is the best option,
>>> as it is the most intuitively obvious and least likely to cause
>>> problems if you ever create aggregations over longer periods.
>>>
>>> Cheers,
>>>
>>> --Seth
>>>
>>> On Fri, 15 Mar 2013 22:45:39 +0100
>>> Andreas Hilboll <lists at hilboll.de> wrote:
>>>> Hi,
>>>>
>>>> I want to store monthly averages of gridded satellite measurements of
>>>> atmospheric trace gas columns. I'm wondering how I should specify the
>>>> time axis, i.e. set the time for each monthly aggregate to the first, or
>>>> the central, or the last day of the month. How should I specify that the
>>>> values are actually monthly averages?
>>>>
>>>> Thanks for your ideas!
>>>> Cheers, Andreas.
>>>> _______________________________________________
>>>> CF-metadata mailing list
>>>> CF-metadata at cgd.ucar.edu
>>>> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
>>>
>>
>
Received on Fri Mar 15 2013 - 17:07:01 GMT
