Opened 2 years ago

Closed 17 months ago

#6030 closed enhancement (fixed)

CF geostationary projection

Reported by: lmajewsk Owned by: warmerdam
Priority: normal Milestone: 2.1.0
Component: OGR_SRS Version: 2.0.0
Severity: normal Keywords:
Cc:

Description

Hi, The GDAL and netCDF-Java handling of the CF geostationary projection seem to differ.

For GDAL to match the CF proposal (accepted) the grid_mapping_name should be changed from "geostationary_satellite" to "geostationary".

An additional sweep_angle_axis field (default="y") should also be specified. (Apparently proj4.8.0 supports the "sweep" keyword https://trac.osgeo.org/proj/wiki/proj%3Dgeos#Noteonsweep, PJ_geos.c). However, WKT/osr/ogr do not support sweep at the moment (that I can see).

There seem to be some differences in the WKT and CF projection attribute names:

  • "satellite_height" (WKT) should be specified using "perspective_point_height" attribute (CF, netCDF-java)
  • "longitude_of_central_meridian" (WKT) should be "longitude_of_projection_origin" attribute (CF, netCDF-java)

I had a look at some of the source and can see where a few changes could be made, but I'm not across all the interconnected components of GDAL (ogr/srs/cf). I would be happy to help test.

Cheers, Leon

Change History (3)

comment:1 Changed 17 months ago by Even Rouault

Milestone: 2.1.0
Type: defectenhancement

Here's my attempt at fixing this :

trunk r33504 "OSR: on import of +proj=geos, if +sweep=x is used then store it as a proj4 extension node (#6030)" trunk r33505 "netCDF: add support for the geostationary projection (#6030)"

Only round-tripping inside GDAL tested for netCDF support.

comment:2 Changed 17 months ago by Even Rouault

trunk r33506 "netcdf_cfchecks.py: add geostationary (#6030)"

comment:3 Changed 17 months ago by Even Rouault

Resolution: fixed
Status: newclosed

Closing. Feedback from reporter would be appreciated though

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