This page was created to list/track progress as a supplement to work in October 2011 on wiki:NetCDF_Improvements, specifically wiki:NetCDF_exportUpdateChanges.

The list of supported CF-1.5 projections is shown at ​http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.5/apf.html .

The table below shows tested ability to export projections from a GDAL raster - originally in GeoTIFF - to NetCDF CF-1.5 in each supported projection.

Hopefully the shorthand projection names listed below are fairly self-explanatory - they've been listed in the same order as that shown on the CF-1.5 appendix page.

Note: the current import capability has been tested to be the inverse of the export capability. If and when we are able to test capability to import NetCDF variants that don't have a direct CF-1 equivalent, we should add a supplementary table.

Projection	Export- CF compliance	Export - openable by NetCDF Java	Updated	Note
AEA	Yes	Yes	18/10/11	Tested regular 2SP version - see AEA note below.
AzEq	Yes	No	18/10/11	See (1) below
LAzEqA	Yes	Yes	18/10/11
LC-2SP	Yes	Yes	18/10/11	Tested 2SP version - CF-1 claims to have a 1SP version, but params quite different to OGC WKT so not tested. See note below.
LCEA	Yes	No	18/10/11	Tested regular OGC WKT with 1 std parallel version (CF-1 has alternative, see notes below). See (1) below re NetCDF-Java loading.
M-1SP	Yes	No	18/10/11	See (1) below
M-2SP	Yes	Yes*	18/10/11	Parameters appear correct, loads in NetCDF Java and IDV, but appears translated slightly (a few arc-minutes) from expected position
Ortho	Yes	Yes	18/10/11
Polar St	Yes*	No*	18/10/11	See projection comments below re parameters. File opens in IDV, but then
Rot Pole	No	No	18/10/11	See projection comments below
St	Yes	Yes	18/10/11
TM	Yes	Yes	18/10/11

General notes:

(1) For projections that won't load correctly as referenced grids in NetCDF Java, we've contacted the developers to ask for clarification/testing support. In most cases, the CF-1 attributes seem appropriate.

Issues with CF-1 implementation of specific projections:

• AEA (Albers Equal Area): The OGC WKT version has 2 Std parallels - whereas the CF-1.5 version says it can have either 1 or 2 std parallels. How would the 2SP version be converted to a CF 1SP version, and vice-versa?
• LCC (Lambert Conformal Conic): The OGC WKT 'Lambert_Conformal_Conic_2SP' maps clearly to LC in CF-1 with 2 std parallels. The CF-1 spec claims that a 1SP version can be used, but it doesn't include a 'scale_factor' as does the OGC WKT 'Lambert_Conformal_Conic_1SP'. Is there a way to do this conversion?
• LCEA (Lambert Cylindrical Equal Area): The CF-1 conventions claim this can be encoded with a 'scale_factor_at_projection_origin' alternative to standard parallel - how would this conversion be done back from OGC WKT?
• Polar St (Polar Stereographic): This projection's parameters in CF-1 are quite unusual, and significantly different from ​http://www.remotesensing.org/geotiff/proj_list/polar_stereographic.html. In particular finding a CF-1 equivalent for 'latitude of natural origin' is proving difficult.
• Rot pole (Rotated Poke): Not able yet to test: as seems GDAL needs support of advanced proj4 strings that can handle rotated coord systems.