Folks:
Regarding the geosync request for comment .....
In the case of GOES-R (and also Meteosat) our coordinate variable values are N/S elevation angle and E/W scanning angle, which can be syntactically valid values albeit off the disk of the earth.
However, it is very possible that there will be a need for a hemispheric product with lat/lon coordinate variables. Currently, GOES-R does not have this need (although we did before there was a change to the requirements). In this case, there would be a need to have some type of missing value for the coordinates of these off disk pixels in the earth bounding rectangle/square.
very respectfully,
randy
Randy C. Horne (rhorne at excaliburlabs.com)
Principal Engineer, Excalibur Laboratories Inc.
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---------- Original Message ----------------------------------
From: John Caron <caron at unidata.ucar.edu>
Date: Mon, 26 Mar 2012 08:28:16 -0600
>On 3/26/2012 2:24 AM, Jonathan Gregory wrote:
>> Dear Ros
>>
>> Regarding this requirement:
>>
>>> 9.6 Where any auxiliary coordinate variable contains a missing value, all
>>> other coordinate, auxiliary coordinate and data values corresponding to that
>>> element should also contain missing values.
>> Appendix A notes that missing data is allowed in aux coord vars only in the
>> case of discrete sampling geometries. This means the checker could regard it as
>> an error also if it finds any missing data in aux coord vars, unless a valid
>> featureType att is present, arising from 9.6, in addition to the above.
>>
>> However, I think the convention should be clear that this is not allowed except
>> for discrete sampling geometries, so I'll open a defect ticket for that.
>>
>> Best wishes
>>
>> Jonathan
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>
>I think this may be more complicated.
>
>Consider a geosynch satellite with lat/lon aux coordinates. the nature
>of the image is that there are many points around the outside of the
>image that are not located on the earth. i dont see any good choices
>other than to put missing values there for lat/lon..
>
>To add insult to injury, it seems possible that there are valid data
>values at these locations. Not sure about that however. Can anyone with
>geosynch data expertise comment?
>
>It seems at minimum this is another case where missing values in aux
>coordinates are needed.
>
>
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..............End of Message ...............................-->
Received on Mon Mar 26 2012 - 09:11:44 BST
