Forecast Model Run Datasets; was: More comlicated data structure

[John Caron]

Hi Lukas:

You might want to look at this:

  http://www.unidata.ucar.edu/software/netcdf/ncml/v2.2/FmrcAggregation.html

The first part talks about these kinds of Forecast Model Run Dataset; the remaining is about aggregation that may not be useful.

Also, the CF group is debating now whether a convention is needed for this case. If you are following that group, you might want to put your opinion in.

http://www.cgd.ucar.edu/cms/eaton/cf-metadata/CF-1.0.html

Lukas Lehner wrote:
> Hi Don
> 
> Thank you for quick and satisfactory answer :)
> More stuff below.
> 
> Don Murray napsal(a):
> 
>> Hi  Lukas-
>>
>> Lukas Lehner wrote:
>>
>>> The new version 2.2 (beta) solved some of my issues, but not all of 
>>> them.
>>> All of the datasets i can find are basically grids put on timeline. 
>>> Also CF convention and other sources are pretty much based on this 
>>> scheme.
>>
>>
>> Which is why we took that route in the IDV. ;-)
>>
>>> Yet is there any way to make dataset - and view it with IDV of course 
>>> - for prediction environment as this?
>>> time axe - actual time of prediction
>>> horizont axe - time step in prediction
>>> 2D or 3D grid.
>>
>>
>> Are you talking about having a 2D time dimension - model run time
>> and forecast hour?  Some work has been done on this at Unidata to
>> view collections of model data where you could say:
>>
>> - show me all forecasts that are valid at a particular time
>> - show me all the  12 hour forecasts for the collection.
>>
>> However, this is a fundamental change in the way we handle
>> time in the IDV and is going to take some work to get that
>> functionality in the  IDV.
> 
> 
> I see....
> So I have redesign the archive.
> 
>>
>>> One can make this kind of structure quite easily , but to view it 
>>> with common tools seems impossible.
>>
>>
>> What would this structure look like to you in a netCDF file?
> 
> 
> like this
> 
> Dataset {
>     String time[time = 881];
>     Float32 t2[time = 881][rdim = 79][dimi = 67][dimj = 79];
> }
> 
> time is run time
> rdim is forecast hour
> them just the grid
> 
> Lukas
> 
>>
>>> This feels to me like usual situation in storing prediction data.
>>
>>
>> The default view of the data is to show the valid time, not
>> the model run+forecast hour.
>>
>> Don
>> *************************************************************
>> Don Murray                               UCAR Unidata Program
>> dmurray at unidata.ucar.edu                        P.O. Box 3000
>> (303) 497-8628                              Boulder, CO 80307
>> http://www.unidata.ucar.edu/staff/donm
>> *************************************************************
>>
>>
> 
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