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Re: CF-1.4 conventions for lat/lon datum.

A couple sentences to summarize the spatial reference issues we are having:
Hydrological Modeler's have an interest in data and model output stored on 
(spherical lat/lon) meteorological grids. Are observations and forcings used to 
populate these spherical grids transformed into spherical geocentric 
coordinates? If not, should model results be assumed to exist on the spherical 
datum or the original spheroidal one? 

I could meet Tuesday July 14th or the 15th. I could also move my travel dates 
to be there Tuesday the 20th. 

Thanks,

Dave

On Jun 30, 2010, at 2:04 AM, john caron wrote:

> David Blodgett wrote:
>> Sounds good John, 
>> We'll need to discuss the approach here. I think there is probably a great 
>> opportunity for some cross-discipline collaboration.
>> 
>> It may not be as simple as refactoring the transformations to handle 
>> meteorological -> geographic grids. I have yet to get a firm answer to this, 
>> but I have a suspicion that in some cases, it may make the most sense to use 
>> the current implementation. 
>> My assumption is that the forcings and observations used by meteorological 
>> modelers were not necessarily converted to spherical coordinates. 
>> Calculations and model runs are performed using spherical math though. I am 
>> not certain about this, but if it is the case, the most appropriate approach 
>> would be to assume the positions are actually from the original datum of the 
>> populating data or model forcing.
>> 
>> Do you know, or have a contact who could definitively address this?
> Large scale models assume a spherical earth, for speed im sure. Not sure 
> about observational forcings, but i have heard the above characterization 
> before. I can post to CF list to see who can help. Can you formulate a 
> sentence or two about what problem we are trying to solve?
>> 
>> I'm going to be in Boulder before and after the weekend of the 17th of July, 
>> maybe a good opportunity to chat about this and other things we would like 
>> to collaborate on?
> this would be good. im unavailable 16-19, when are you available? ethan?