Summary previous session 1 3 D:\ tools models add meta information netCDF on web server transform to netCDF netCDF on OPeNDAP server data data providers = data users 2a use tools > Extract Transform LoadProvide 2b read data 2c > save as netCDF

Current session: using netCDF from others 1 3 D:\ tools models add meta information netCDF on web server transform to netCDF netCDF on OPeNDAP server data data providers = data users Extract Transform LoadProvide 2

netCDF > OPeNDAP netCDF files are already a powerfull file format to share self-describing all meta-info included lots of free inspection tools but … often netCDF files can be very big and you just want to check the meta-info (at first) or peek at a subset of the data, while keeping all meta-info instead of downloading all GB’s OPeNDAP solves this for free because netCDF is an open standard A bunch of netCDF files = a hierarchical database no difficult oploading, just copy to file server (ftp, scp) and the dynamic OPeNDAP server sees it

Just have a look at an OPeNDAP sever OpenEarth.deltares.nl > data > opendap server (THREDDS) (HYRAX) test server Data organized per copyright owner Synchonized with file simple server (still to do)

netCDF though OPeNDAP File structure can be scrolled in browser netCDF (*.nc) files offer special functionality Extract meta-info online in browser Get full netCDF: large files often used Get subset of netCDF: peeking large files Get subset as ASCII Paste url into ncBrowse matlab No need to store copy of data: one url commands in url

Example: orthogonal grid: ncBrowse

Example: orthogonal grid: Matlab

Example: timeseries grid: ncBrowse waterbase.nl NOTE: ncBrowse cannot handle really large datasets (e.g. timeseries of HvH), but Matlab can.

Example: timeseries grid: Matlab NOTE: Matlab handles also laaaarge datasets (e.g. timeseries HvH).

Example: coastlines: ncBrowse

Example: coastlines: Matlab Note: in fact, some people say GIS data should not end up in netCDF, but in shape Files. Yet shaperead.m is not standard Matlab (mapping toolbox) and netCDF is fast, and offers meta-data. oreviewing. However, OpenGIS WFS services allows do Offer this option too.

Summary: using netCDF from others via web 1 3 D:\ tools models add meta information netCDF on web server transform to netCDF netCDF on OPeNDAP server data data providers = data users Extract Transform LoadProvide 2

Now the fun starts Easily feed models: meteo Make inventory of dataset Make easily KML files (Thijs) fore Google Earth. Add plot to Google Mass (Thijs)