[CF-metadata] Questions on cell boundaries

From: Thomas Lavergne <t.lavergne>
Date: Wed, 17 Feb 2010 13:36:21 +0000 (UTC)

Dear all,

I do not think someone reacted on my concern/question about non-polygonal cell boundaries. Maybe I am the only one with this issue or maybe this topic went un-noticed because of heavy load on the CF list at that time.

I thus re-post my original message in hope that someone will comment on it (or point me to an archived thread that I did not yet see).

Original post:

> Hi everyone,
>
> I refer to Chapter 7 on "Data Representative of Cells", 7.1 "Cell
> Boundaries".
>
> The specification of those boundaries seems to biased towards
> polygonal boundaries (in the case of a 2D surface). This covers
> certainly most of the needs but what happens if the cell is defined as
> a disc of radius x km (with center at the coordinate value)?
>
> Of course, I can always give 10 to 10,000 vertices that will
> approximate my disc but it does not sound very neat nor efficient. We
> would have to somehow move away from listing the 'bounds' and start
> describing the shape of the cell (disc, ellipse, rectangle, etc...).
> Note that the concepts of "cell measures" and "cell methods" would
> still perfectly hold.
>
> One example of such a dataset would be one where at each grid location
> we report the mean/minimum/maximum temperature or pressure recorded by
> any station found in a radius of, say, 30 km around the central
> point.
>
> Another example is satellite data in swath projection where each
> record is associated to a Field Of View, which is often approximated
> as a an ellipse.
>
> Did someone give it a thought already?
Received on Wed Feb 17 2010 - 06:36:21 GMT