Hi all,
I would like to point out the following 3 tickets I have created in
trac, regarding Projections and WKT (Well-Known Text) representation.
The first two have been created 1 month ago and there has been almost
no responses.
1) fix documentation and definitions of 3 grid mapping definitions
https://cf-pcmdi.llnl.gov/trac/ticket/75
This has been discussed in the list:
http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2011/027605.html
It addresses some errors and confusion identified in the definitions
of 3 projections.
2) Add sinusoidal projection
https://cf-pcmdi.llnl.gov/trac/ticket/77
The sinusoidal projection is used in most of MODIS products. Only one
response so far - Jonathan has approved it.
3) Add missing CF parameters to translate Coordinate Reference System
properties to/from OGC Well-Known Text format
https://cf-pcmdi.llnl.gov/trac/ticket/80
I created this ticket yesterday, and it has been discussed some time
ago on this list:
http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2011/027499.html
With Jonathan's help I have come up with a proposal to add CF
grid_mapping attributes that are missing to translate a projected or
geographic coordinated system to/from OGC WKT.
The following grid_mapping attributes would be added and described in Table F1
horizontal_datum_name
towgs84 (a double-precision array, with 3, 6 or 7 values)
prime_meridian_name
reference_ellipsoid_name
projected_coordinate_system_name
geographic_coordinate_system_name
I have also added substantial supporting documentation for CF/WKT
translation at
https://cf-pcmdi.llnl.gov/trac/wiki/Cf2CrsWkt
This ticket is related to:
https://cf-pcmdi.llnl.gov/trac/ticket/69
Ticket #69 is different, in that it allows to store the entire WKT
string in a grid_mapping attribute. This ticket aims to by-pass the
need for WKT representation in CF and the potential confusion, errors
and inconsistencies that can result from multiple definitions
(standard CF and the WKT).
Any comments are welcome!
Regards,
Etienne
Received on Wed Mar 07 2012 - 08:35:18 GMT
