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Published byEdwina Scott Modified over 9 years ago
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Summary previous session 1 3 D:\... 3 http://… 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
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Current session: using netCDF from others 1 3 D:\... 3 http://… 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
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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
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Just have a look at an OPeNDAP sever OpenEarth.deltares.nl > data > opendap server http://opendap.deltares.nl:8080/thredds (THREDDS) http://opendap.deltares.nl:8080/opendap (HYRAX) test server Data organized per copyright owner Synchonized with file simple server (still to do)
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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
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Example: orthogonal grid: ncBrowse http://iridl.ldeo.columbia.edu/SOURCES/.WORLDBATH432/.bath/dods
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Example: orthogonal grid: Matlab http://iridl.ldeo.columbia.edu/SOURCES/.WORLDBATH432/.bath/dods
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Example: timeseries grid: ncBrowse waterbase.nl NOTE: ncBrowse cannot handle really large datasets (e.g. timeseries of HvH), but Matlab can.
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Example: timeseries grid: Matlab NOTE: Matlab handles also laaaarge datasets (e.g. timeseries HvH).
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Example: coastlines: ncBrowse
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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.
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Summary: using netCDF from others via web 1 3 D:\... 3 http://… 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
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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)
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