The HDF Group ESIP Summer Meeting Easy access HDF files via Hyrax Kent Yang The HDF Group 1 July 8 – 11, 2014

ESIP Summer Meeting Outline Why OPeNDAP? Hyrax features Hyrax modules Demos Suggestions July 8 – 11,

ESIP Summer MeetingJuly 8 – 11, Why OPeNDAP? Check metadata remotely (in various forms) Obtain the subset of data easily and efficiently Hide the original data sources netCDF, HDF4, HDF5 or GeoTiFF, GRIB Many popular earth science tools can visualize and analyze the data via OPeNDAP OPeNDAP output(including subsets) can be downloaded as other formats

ESIP Summer MeetingJuly 8 – 11, Doesn’t help Great!

ESIP Summer MeetingJuly 8 – 11, The visualization of HDF(5) data via Hyrax What NASA users request the most HDF(5) Hyrax modules

ESIP Summer Meeting Helpful Hyrax feature – BES keys BES keys to dynamic change the program flow Easy for users to choose what they want Easy for developers to add/revise features requested by users July 8 – 11,

ESIP Summer Meeting Example on using BES keys July 8 – 11, Float /CERES_Unfiltered_Radiances/all_toa_sw_rad[24][180][360] Float CERES_Unfiltered_Radiances_all_toa_sw_rad[gmt_hour_index = 24][latitude =180][longitude= 360]

ESIP Summer Meeting Hyrax modulation Core framework implemented in C++ Just need to provide DDS, DAS and Data to Hyrax libdap and BES A handler can be sophisticated HDF handler examples Retrieve latitude and longitude for HDF-EOS grid Interpolate the latitude and longitude for HDF-EOS swath with dimension map Make sure the dimensions, variable names and attributes follow CF conventions July 8 – 11,

ESIP Summer MeetingJuly 8 – 11, Non-CF CF Float CERES_Unfiltered_Radiances_all_toa_sw_rad[gmt_hour_index = 24][latitude =180][longitude= 360] Float /CERES_Unfiltered_Radiances/all_toa_sw_rad[24][180][360]

ESIP Summer Meeting Demos – HDF-EOS2 (AIRS grid) July 8 – 11,

ESIP Summer Meeting Demo 2 – HDF-EOS2 (MODIS swath) July 8 – 11, Swath with Dimension Map

ESIP Summer Meeting Demo 3 – HDF-EOS5 (OMI grid) July 8 – 11,

ESIP Summer Meeting Hyrax modules that help the easy access Filenet CDF module Can download DAP output as a netCDF-3 or netCDF- 4 classic files NcML module Add/delete/revise metadata information of the data source Aggregate granules July 8 – 11,

ESIP Summer Meeting Demo July 8 – 11, GPM level 1B(HDF5)

ESIP Summer Meeting HDF(5) and file netCDF demo FilenetCDF module can work with the HDF handlers to download the HDF files or subset of the files as netCDF-3 or netCDF-4 classic files that follow the CF conventions July 8 – 11,

ESIP Summer Meeting HDF(5) and NcML demo NcML module can be used with HDF handlers to provide the missing CF information AVHRR example July 8 – 11,

ESIP Summer Meeting HDF(5), file netCDF and NcML demo HDF handlers, NcML module and file netCDF module can work together AVHRR example July 8 – 11,

ESIP Summer Meeting Summary of modules to serve HDF files July 8 – 11, Hyrax core HDF(5) files Main engine HDF(5) handlers Supplement Info NcML DAP clients (IDV, Ferret, Panoply, IDL…...) netCDF files Alternative output File netCDF

ESIP Summer Meeting Demo - Beyond the web service BES standalone program Connect the HDF handlers, the file netCDF module and the NcML module End users can build Hyrax and use this program as a command-line tool Can it be a standalone tool? July 8 – 11, besstandalone -c /etc/bes/bes.conf -i in4-GPM-l1b > GPM-l1b.nc4

ESIP Summer Meeting Future - Performance Improve the BES caching mechanism Critical for large file access and aggregation service July 8 – 11,

The HDF Group ESIP Summer Meeting Earth Science Group Ted Habermann Aleksandar Jelenak H. Joe Lee Joel Plutchak John Readey Kent Yang 21 July 8 – 11, 2014