Reprojecting datasets documentation and implications for global datasets about project-support-wp8

[mh-geus-dk]

Setting aside that there is no EPSG:900913 :)

Yes, EPSG:900913 is deprecated and replaced by EPSG:3857 but nevertheless still being used by many.

Does that mean that other projections will be allowed to be selected, if so which ones will be selectable?

In principle, the web-GIS can display maps in all EPSG codes but we recommend sticking to EPSG:3034 because it is well-tested and other projections will involve work for GIP to adjust base maps, tools, and other functionality.

If datasets are provided as services for consumption by the EGDI portal I can see that they must provide support for the supported projections, but I don't understand the implications for supplied datasets. Surely the EGDI platform services/API will do the necessary reprojections. For HOVER we have a global dataset, whilst EPSG:3034 is limited to Europe, what are the implications for the dataset?
Global data sets can be delivered in e.g. EPSG:4326 or EPSG:3857. In case your data set is contains lines or polygons that cross the poles it's more tricky and we might need to investigate further in order to give the best advise.

[nmtoken]

There never was an EPSG:900913 not that it's deprecated, it never existed, that is, there never was a code 900913 in the EPSG Geodetic Parameter Dataset; I know though that doesn't stop people advertising that they support it.

EPSG:3857 is not global coverage, it cuts off the poles, which is problematic for some Arctic (and less important for Europe Antarctic) datasets.

In principle, the web-GIS can display maps in all EPSG codes but we recommend sticking to EPSG:3034 because it is well-tested and other projections will involve work for GIP to adjust base maps, tools, and other functionality.

I'm still not sure what this means for portal functionality, does it mean that a viewer can request to view any data in any EPSG code, and indeed any CRS code, (for example CRS:84 used by GeoJSON), in the Web GIS, or does it mean that the Web GIS will only support a limited number of projections, (the by default list)?

For the HOVER dataset (NetCDF or GeoTIFF) data will be in EPSG:4326, if viewing the data in EPSG:4326 is possible in the Web GIS then there is no issue. Reprojecting will be possible, but likely problematic