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Feature Collections Subsetting

Feature Collections Subsetting. 1. Overview 2. NCSS 2.1. Dataset description 2.2. Grid requests 2.3. Grid as point requests 3. CdmrFeature. Feature Collections Subsetting 1.Overview. TDS Subsetting services: - Spatial coordinates: - NetCDF Subset Service: NCSS

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Feature Collections Subsetting

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  1. Feature Collections Subsetting 1. Overview 2. NCSS 2.1. Dataset description 2.2. Grid requests 2.3. Grid as point requests 3. CdmrFeature

  2. Feature Collections Subsetting1.Overview • TDS Subsetting services: -Spatial coordinates: - NetCDF Subset Service: NCSS - CDM Remote Feature: CdmrFeature - Array index subsetting: - OpenDAP

  3. Feature Collections Subsetting1.Overview • NetCDF Subset Service: NCSS - Subset on Grid feature collections. - Allows grid subsetting and point extraction.

  4. Feature Collections Subsetting1.Overview • Cdm Remote Feature: CdmrFeature - Subset on point feature collections. - Experimental

  5. Feature Collections Subsetting2.0 NCSS Configuration • - threddsConfig.xml • Enabling the service: <NetcdfSubsetService> <allow>true</allow> <!--maxFileDownloadSize>300 MB</maxFileDownloadSize --> </NetcdfSubsetService> • Enabling netcdf4 as output (optional): <Netcdf4Clibrary> <libraryPath>C:/cdev/lib/</libraryPath> <libraryName>netcdf4</libraryName> </Netcdf4Clibrary> - Catalogs: <service name="subsetServer" serviceType="NetcdfSubset" base="/thredds/ncss/grid/" />

  6. Feature Collections Subsetting2.1. NCSS Dataset description • Document that provides all the information to formulate valid requests • Contains: • coordinate axes • variables • spatial ranges • supported formats • ...

  7. Feature Collections Subsetting2.1. NCSS Dataset description • Two views of the dataset description: • Form view: • Web interface for accessing the service • Simple grid pre-visualization • Xml document

  8. Feature Collections Subsetting2.2. NCSS Grid Subsetting Subsetting on variables • Parameter var (mandatory) • Variables as declared in the dataset description separated by “,” - var=all - var=Pressure_surface,Temperature_tropopause

  9. Feature Collections Subsetting2.2. NCSS Grid Subsetting Spatial subsetting • Lat/Lon bounding box: • params: north, south, west, east (all of them!!!) • var=Pressure_surface,Temperature_tropopause&north=80&south=60&west=200&east=280 • Projection bounding box • params: minx, maxx, miny, maxy (all of them!!!) • var=Pressure_surface,Temperature_tropopause&minx=0&maxx=3000&miny=-1000&maxy=0

  10. Feature Collections Subsetting2.2. NCSS Grid Subsetting Temporal subsetting • By default closest time to present • All range, parameter temporal: • temporal=all • Single time, parameter time (all times in W3C format): • time=2012-10-22T18:00:00Z • Time range (all times and durations in W3C format): • params: time_start, time_end, time_duration (two of them!!!): • time_start=2012-10-22T15:00Z&time_duration=P1DT12H

  11. Feature Collections Subsetting2.2. NCSS Grid Subsetting Vertical subsetting • Default: all vertical levels • vertCoord: only on variables with same vertical levels • vertCoord=400

  12. Feature Collections Subsetting2.2. NCSS Grid Subsetting Vertical subsetting: transformations • If a vertical transformation is defined in the dataset (CF-1.0) all the variables needed to perform the transformation are included in the grid output • Example: http://geoport-dev.whoi.edu/thredds/ncss/grid/coawst_2_2/fmrc/coawst_2_2_best.ncd/dataset.html

  13. Feature Collections Subsetting2.2. NCSS Grid Subsetting Supported Formats • netCDF, netCDF4 • NetCDF4 has to be configured in threddsConfig.xml • Parameter: accept - accept=netcdf - accept=netcdf4

  14. Feature Collections Subsetting2.3. NCSS Grid As Point Grid As Point • Extracts point features from grids • Parameters latitude and longitude to define the requested point - latitude=86&longitude=220

  15. Feature Collections Subsetting2.3. NCSS Grid As Point Vertical levels • All vertical levels are returned by default • Parameter vertCoord can be used on variables with different vertical levels.

  16. Feature Collections Subsetting2.3. NCSS Grid As Point Vertical levels • If a vertical transformation is defined in the dataset the service returns: • The values of the dimensionless vertical coordinate. • The actual values of the vertical levels.

  17. Feature Collections Subsetting2.3. NCSS Grid As Point Supported Formats • csv, xml, netCDF, netCDF4 • NetCDF4 has to be configured in threddsConfig.xml • Parameter: accept - accept=netcdf - accept=netcdf4 - accept=xml - accept=csv

  18. Feature Collections Subsetting3. CdmrFeature • CdmrFeature: subsetting on point feature collections • Still under development. Unstable. • Eventually, NCSS and CdmrFeature will merge into one single API for subsetting grid and point features.

  19. Feature Collections Subsetting3. CdmrFeature • Example requests: Metadata requests • Dataset form • req=form • Dataset description (capabilities): • req=capabilities • Stations: • req=stations

  20. Feature Collections Subsetting3. CdmrFeature • Example requests: Metadata requests • Dataset form • req=form • Dataset description (capabilities): • req=capabilities • Stations: • req=stations

  21. Feature Collections Subsetting3. CdmrFeature Data requests: • req=data • Spatial subsetting: • variables=some • spatial=bb • temporal=range http://thredds.ucar.edu/thredds/cdmrfeature/nws/metar/ncdecoded/Metar_Station_Data_fc.cdmr?req=data&variables=some&var=air_temperature&var=cloud_area_fraction&spatial=bb&north=41&west=-109&east=-102&south=37&temporal=range&time_start=2013-07-09T23:00:00Z&time_end=2013-07-10T00:00:00Z&time=2013-05-10T00:00:00Z&accept=csv

  22. Feature Collections Subsetting3. CdmrFeature • Data requests: • Stations subsetting: • spatial=stns • stn=LEST,LEVX,LECO http://thredds.ucar.edu/thredds/cdmrfeature/nws/metar/ncdecoded/Metar_Station_Data_fc.cdmr?req=data&variables=some&var=air_temperature&spatial=stns&stn=LEST,LEVX,LECO&temporal=range&time_start=2013-07-09T23:00:00Z&time_end=2013-07-10T00:00:00Z&time=2013-05-10T00:00:00Z&accept=csv

  23. Feature Collections Subsetting3. CdmrFeature • Data requests: • Closest station: • spatial=point • Latitude=39.98 • longitude=-105.02 http://thredds.ucar.edu/thredds/cdmrfeature/nws/metar/ncdecoded/Metar_Station_Data_fc.cdmr?req=data&variables=some&var=air_temperature&spatial=point&latitude=39.98&longitude=-105.02&stn=&temporal=range&time_start=2013-07-09T23:00:00Z&time_end=2013-07-10T00:00:00Z&time=2013-05-10T00:00:00Z&accept=csv

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