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GrADS/DODS Server Developed by SIESIP Team

GrADS/DODS Server Developed by SIESIP Team. Brian Doty (COLA) SIESIP: GMU, COLA, GSFC, Udel COLA: Center for Ocean-Land-Atmosphere Studies. GrADS and DODS. Data Interoperability Distributed Data Distributed Analysis. Information Technology: GrADS. Visualizing. Maps, Charts, Animations.

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GrADS/DODS Server Developed by SIESIP Team

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  1. GrADS/DODS Server Developed by SIESIP Team Brian Doty (COLA) SIESIP: GMU, COLA, GSFC, Udel COLA: Center for Ocean-Land-Atmosphere Studies

  2. GrADS and DODS Data Interoperability Distributed Data Distributed Analysis

  3. Information Technology: GrADS Visualizing Maps, Charts, Animations Interactive Quantitative INTEGRATED USER INTERFACE Analyzing Accessing, Subsetting 4D Grids In Situ Obs Images { Expressions, Functions of Original Variables General slices of User Definable, Extensible Arbitrary Domains Optimized for Typical Queries

  4. GrADS Usage • “Natural” user interface for scientific computations, and graphical production • Used at over 100 laboratories worldwide • Used by over 1000 scientists worldwide • E.g., J. Climate - Over ½ of all figures (and computations?) produced using GrADS • Handles GRIB, binary (model output) formats in “native” mode • Widely used for analysis and display of data from the National Weather Service, other WMO sources

  5. GrADS Analysis Model • ENABLES VERY SOPHISTICATED ANALYSIS TASKS • IN A HIGHLY ENCAPSULATED WAY • Scientists only need to specify: • dimension constraint • list of data sets • GrADS expression • This unique, innovative approach to geophysical data analysis is the major reason for GrADS’ popularity.

  6. Data Access/Interoperability/Analysis • Level 0: FTP & basic Web capability. • Level 1: DODS server concept: general data subsetting; metadata. Client can support data interoperability. • Level 2: Analysis server. Uses GrADS unique encapsulated analysis capability. • Example: • Calculate – at the server! – sea level pressure anomaly over N. America when tropical Pacific SSTA > 1.0. Return the result – as data ! – to the desktop. • Size of data sets: 3GB (Level 0) • Data processed at server: 5 MB (Level 1) • Returned to client: 10KB (Level 2)

  7. Examples of GrADS Used on the Web to Deliver Images NCDC - http://www.ncdc.noaa.gov/onlineprod/prod.html CPC - http://www.cpc.ncep.noaa.gov/products/ CDC - http://www.cdc.noaa.gov/USclimate/ DAO – Terra NCDC NCEP – CPC NOAA – CDC DOLMS - http://dao.gsfc.nasa.gov/monitoring/ DOLMS Ozone - http://dao.gsfc.nasa.gov/monitoring/

  8. Data Access/Interoperability/Analysis • Level 0: FTP & basic Web capability. • Level 1: DODS server concept: general data subsetting; metadata. Client can support data interoperability. • Level 2: Analysis server. Uses GrADS unique encapsulated analysis capability. • Example: • Calculate – at the server! – sea level pressure anomaly over N. America when tropical Pacific SSTA > 1.0. Return the result – as data ! – to the desktop. • Size of data sets: 3GB (Level 0) • Data processed at server: 5 MB (Level 1) • Returned to client: 10KB (Level 2)

  9. DODS • Client/server architecture • http protocol • Generic, flexible data model • Metadata distribution capability • “Open your data set with a URL instead of a filename”

  10. Client GrADS handles HTTP, unpacks data Matlab DODS client libraries IDL data appears to client as local file, in a standard format (i.e, NetCDF, etc.) etc.. GrADS-DODS Client-Server datasets in any format supported by GrADS GrADS-DODS Server extracts meta-data and subsets maps DODS requests to GrADS services parses requests, packages data handles HTTP protocol binary data GrADS batch mode interface code DODS server libraries Java servlet GRIB data NetCDF data HDF data etc.. DODS requests and compressed data exchanged via HTTP internet DODS = Distributed Oceanographic Data SystemA protocol for transferring data and metadata over the internet independent of file format; see http://www.unidata.ucar.edu/packages/dods/ Joe Wielgosz: 5/25/00

  11. An Example: Analysis of Multiple Remote Data Sets PMEL CDC DAO, NCEP or COLA GMU

  12. Data Interoperability Example: Data from two Servers sdfopen http://cola8... set gxout shaded set time jul1980 d p sdfopen http://cdc... set gxout contour d prate.2*86400*31

  13. Data Access/Interoperability/Analysis • Level 0: FTP & basic Web capability. • Level 1: DODS server concept: general data subsetting; metadata. Client can support data interoperability. • Level 2: Analysis server. Uses GrADS unique encapsulated analysis capability. • Example: • Calculate – at the server! – sea level pressure anomaly over N. America when tropical Pacific SSTA > 1.0. Return the result – as data ! – to the desktop. • Size of data sets: 3GB (Level 0) • Data processed at server: 5 MB (Level 1) • Returned to client: 10KB (Level 2)

  14. internet Client GrADS Matlab DODS client libraries IDL data appears to client as local file, in a standard format (i.e, NetCDF, etc.) etc.. GrADS-DODS Analysis Server Server datasets in any format supported by GrADS performs analysis operations manages sessions, translates dataset names supports extended request types for analysis, upload GrADS data GRIB data GrADS batch mode interface code DODS server libraries Java servlet NetCDF data etc.. Result cache holds temporary data (uploaded, generated by a previous operation, or transferred directly from another server) for use in remote analysis DODS data and requests EncapsulatedAnalysis Requests Joe Wielgosz: 5/25/00

  15. GrADS Analysis Model • ENABLES VERY SOPHISTICATED ANALYSIS TASKS • IN A HIGHLY ENCAPSULATED WAY • Scientists only need to specify: • dimension constraint • list of data sets • GrADS expression • This unique, innovative approach to geophysical data analysis is the major reason for GrADS’ popularity.

  16. Example: Analysis at the Server sdfopen http://cola8.iges.org:9090/dods/_expr_{ssta,z5a} {tmave(maskout(aave(... }{-180:0,0:90,500:500, jan1950,dec1990} set gxout shaded display result

  17. Summary: GrADS-DODS Server • Share data: Interprise-wide; Internet-wide --- data-format independent • Data interoperability: Consistent metadata for many data types • Distributed analysis: Reduces network load; improves interactivity • Automation of analysis techniques: Analysis techniques can be captured in the form of scripts and provided on server and/or client

  18. NCEP Global Weather Forecasts Desktop Weather Forecasting NCEP COLA Global Weather Forecasts GrADS-DODS Server Region-Specific Lateral BCs WWW PC-Based Regional NWP

  19. Sources of Information: SIESIP: http://www.siesip.gmu.edu GrADS and GDS: http://www.iges.org/grads DODS: http://www.unidata.ucar.edu LAS: http://ferret.wrc.noassa.gov

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