John,
The equirectangular projection is a cylindrical equidistant projection
with the standard parallel at the equator.
--Steve
On 7/19/2010 10:48 AM, John Caron wrote:
> On 7/16/2010 2:12 AM, cristina.tronconi at artov.isac.cnr.it wrote:
>> Helloevertybody,
>> I have a netcdf file (chlorophyll gridded satellite daily map) in
>> which I have my variable chl(tim,lat,lon), then the vector of regular
>> lat and a vector for
>> regular lon.
>>
>> My grid mapping is Equidistant Cylindrical. SO in the nc I set as
>> GLOBAL ATTRIBUTE
>> ----------------------------------
>> attname=Conventions
>> value=CF-1.4
>>
>> attname=grid_mapping
>> value=Cylindrical
>> ------------------------------------
>> Some question:
>> 1) A collegue of mine told me that for CF 1.4 the grid_mapping is no more
>> a global attribute but it is a variable attribute named as
>> "grid_mapping_name".
>>
>> BUT I run the CF checker for 1.4 on my file and everything is ok!!!!
>
> The CF checker is limited in understanding the semantics, it often only
> checks syntax.
>
>>
>> SO: Is it still correct /with cf 1.4) to set a global attribute as
>> "grid_mapping" in the case (obviuosly) all the variables use the same
>> grid_mapping? or must I put the same information as variable
>> attribute? in this case, how?
>
> I dont think a global attribute was ever CF compliant. Why do you think
> it was?
>
> In any case, you need to add an attribute to each data variable. see
> examples in section 5.6
>
>> 2) are "Equidistant Cylindrical" and "Cylindrical" still CF valid
>> values for
>> grid_mapping (or grid_mapping name)? I found only "Equirectangular" In
>> the "Content Standard for Digital Geospatial Metadata. Federal
>> Geographic Data Committee, FGDC-STD-001-1998" document mentioned in
>> the Appendix F. Grid Mappings of CF 1.4.
>
> We dont seem to have this projection in our list. Does anyone have
> experience with it?
>
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Received on Mon Jul 19 2010 - 12:49:40 BST
