S3 OLCI reprojected to netcdf4-CF does not always work

When trying to reproject S3 OLCI data, there seems to be a problem with the netcdf4-cf format.

  • Using SNAP and the reprojection module writes a netcdf file that is not recognised by gdal nor ncdump.
  • Using SNAP with graph builder that has a read, reproject and write module writes a netcdf that is ok.
  • Using GPT with the reprojection module does not work as S3 OLCI data is not a valid input format
  • Using GPT with a graph.xml that includes a read, reproject and write module writes a netcdf that is ok.

In the first case, the produced file can be opened in SNAP, so I guess it is a custom format (netcdf-beam?) that is actualy written instead of the netcdf4-cf.

It is not a blocking issue as there is already a workaround or am I doing something wrong?


Hi Davy,

I think a similar problem was reported here:

We had now time to investigate this further. And honestly, I have no idea why it behaves differently.

One thing which could interfere with this problem is this issue:
The output format automatically chosen is not deterministic if it is not specified.

Now, that there are two reports, and it seems to be nothing user specific, I’ve created an issue for this. https://senbox.atlassian.net/browse/SNAP-1079

I’ve answered in the other thread: