| 41 | | * CEA : 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? |
| 42 | | * PS : This projection's parameters in CF-1 are significantly different from http://www.remotesensing.org/geotiff/proj_list/polar_stereographic.html. In particular the CF-1 equivalent for 'latitude of natural origin' seems to be 'standard_parallel'. Note: we have verified the current approach we take to mapping is the same used by at least one other NetCDF CF-1 user in the UCAR NARCCAP project. |
| | 41 | * CEA : 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 from/to OGC WKT (which requires central_meridian and standard_parallel_1)? |
| | 42 | * PS : This projection's parameters in CF-1 are significantly different from http://www.remotesensing.org/geotiff/proj_list/polar_stereographic.html. In particular the CF-1 equivalent for 'latitude of natural origin' seems to be 'standard_parallel'. CF-1 defines either standard_parallel or scale_factor_at_projection_origin, which is incompatible with OGC WKT (and OGR) that requires both. Note: we have verified the current approach we take to mapping is the same used by at least one other NetCDF CF-1 user in the UCAR NARCCAP project. Current implementation (as of Dec. 13) uses the following rules: |
| | 43 | * WKT scale_factor maps to CF scale_factor_at_projection_origin |
| | 44 | * WKT central_meridian maps to CF straight_vertical_longitude_from_pole |
| | 45 | * WKT latitude_of_origin maps to WKT standard_parallel |
| | 46 | * WKT to CF: if WKT latitude_of_origin is positive then CF latitude_of_projection_origin is +90, else it is -90 (North vs. South Pole) |
| | 47 | * CF to WKT: unsupported if standard_parallel is not defined, as OGRSpatialReference::SetPS() requires both CF scale_factor_at_projection_origin |
| | 48 | and standard_parallel |
