[CF-metadata] The use of CF cell constructs for point data

From: John Caron <caron>
Date: Mon, 09 Apr 2012 13:21:44 -0600

On 4/9/2012 1:07 PM, Jonathan Gregory wrote:
> Dear Randy
>
>> The GOES-R system will be producing a hemispheric lightning detection product.
>>
>> It will be an array of lightning detection that occur within some number of seconds across the western hemisphere (i.e. it is not a gridded product).
> Is is a timeseries of values, for probability or number of occurrence or
> yes/no - something like that? If so, I don't think there's a featureType for
> it yet. It's a timeseries which doesn't apply to a station. It would be
> among the list of things not covered by chap 9 yet (see sect 9.1). But you
> don't need to give it a featureType. Chap 9 is primarily for datasets which
> need to use the techniques provided there for saving space.

hmm, my reading is that this would be an appropriate "point" feature
type. Jonathan, not sure why you think not?

>
>> A lightning detection has a center location, and needs to be associated with an area and an interval of time.
>>
>> (2) Use the cell "bounds" construct to capture the time interval.
> Fine. cell_methods should say "time: sum", where time is the name of the time
> dimension. From your description, I think "sum" is appropriate because this
> quantity is extensive in time. The probability would be larger if the interval
> were longer. See App E.
>
>> (3) Use the cell "cell_measures" construct to capture area (i.e. ":cell_measure = area: lightning_detection_area").
> That's not quite right, I think. The entry is to indicate what kind of
> statistic this is, and I would say that again this is extensive. If you
> considered an area smaller than the W hemisphere, the probability would be
> smaller, for instance. So I would suggest "area: sum".

if you are trying to describe the location bounds, a "bounds" on the
lat, lon might be one way to do it?

or perhaps you just want to add some notion of error associated with the
location?


John
Received on Mon Apr 09 2012 - 13:21:44 BST