@leifdenby This PR, based on the current version of master, is failing because the radiosonde datasets hosted on derby.eu are not able to be opened. Should we keep pointing to this data, or should we update to the "version of record" e.g. at AERIS? @d70-t your thoughts?

There was #26 which is not yet resolved. It ended up in a discussion about where / how to provide backup sources of this dataset.

However, as far as I can see, that referenced issue also mentions that there is a new version of the radiosonde dataset which should be included into the catalog and subsequently the old version should probably be removed anyways. I'll try to check if I can make a PR to include the newer radiosonde datasets. That will probably fix this issue as well.