Visualizing and Analyzing ofVisualizing and Analyzing ofHDF-EOS and HDF data with NCLHDF-EOS and HDF data with NCL

Wei Huang, Dave Brown, Mary Haley, Rick Brownrigg

CISL/NCAR

Dennis Shea, Adam PhilipsCGD/NCAR

huangwei@ucar.edu

What is NCLWhat is NCL◦NCL stands for NCAR Command Language

http://www.ncl.ucar.edu for more information

◦NCL is developed at CISL/NCAR, for scientific data analysis and visualization

◦Free available as binaries, open source◦Supports NetCDF (3 and 4), GRIB (1 and 2),

HDF, HDF-EOS 2 and 5 (as Spring of 2010)◦Newly added HDF5 and OpenDap (in 2010)◦High quality graphics◦Lots of example scripts

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HDF-EOS5 Released April, 2010HDF-EOS5 Released April, 2010HDF-EOS5 included NCL◦5.2.0 released in April, 2010◦5.2.1 released in July, 2010

HDF, and HDF-EOS2/5 Examples◦ http://www.ncl.ucar.edu/Applications/HDF.shtml◦Use “ncl_filedump” to check variables in HDF, and

HDF-EOS2/5 files◦Use “ncl_convert2nc” to convert HDF-EOS2/5 and

HDF files to NetCDF files

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HDF-EOS5 SampleHDF-EOS5 Sample

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HDF-EOS5 Sample (continue)HDF-EOS5 Sample (continue)

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HDF-EOS5 Sample (continue)HDF-EOS5 Sample (continue)

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Reflectivity of the ground pixel

HDF5 in Beta ReleaseHDF5 in Beta Release

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Sample Script to Read HDF5Sample Script to Read HDF5 f = addfile(”./data/MOD13A2A.h5", "r”)

◦ printVarSummary(f)

grps = getfilegroups(f, "/", 0)◦ print(grps)

grps2 = getfilegroups(f, "/MODIS_Grid_16DAY_1km_VI", 0)◦ print(grps2)

v1 = f->1_km_16_days_red_reflectance◦ printVarSummary(v1)

vn = grps2(0)+"/1 km 16 days blue reflectance” v2 = f->$vn$

◦ printVarSummary(v2)

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Group in HDF5 and Sample ScriptGroup in HDF5 and Sample Script f = addfile(”./data/NISESSMI.h5", "r")

◦ print(f)

gn = "/Northern Hemisphere” g1 = f=>$gn$

◦ print(g1)

g2n = "/Northern Hemisphere/Data Fields” g2 = g1=>$g2n$

◦ print(g2)

vn = "/Northern Hemisphere/Data Fields/Age" v1 = g1->$vn$

◦ printVarSummary(v1)

v2 = g2->$vn$◦ printVarSummary(v2)

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HDF5 Sample PlotHDF5 Sample Plot

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HDF5 Sample Plot (continue)HDF5 Sample Plot (continue)

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HDF5 Sample Plot (continue)HDF5 Sample Plot (continue)

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HDF5 Sample Plot (continue)HDF5 Sample Plot (continue)

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Read Compound data from HDF5Read Compound data from HDF5

fn = "K1VHR_23SEP2008_2330_L02_SST.h5” f = addfile(fn, "r”)

◦ print(f)

lon1d = f->/SST/SST_Composite.Longitude lat1d = f->/SST/SST_Composite.Latitude sst1d = f->/SST/SST_Dataset.SST

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Print-outPrint-out filename: K1VHR_23SEP2008_2330_L02_SST file global attributes: dimensions: DIM_000 = 36381 variables: group </PRODUCT_INFORMATION> group </PRODUCT_METADATA> group </PRODUCT_METADATA/PRODUCT_DETAILS> group </PRODUCT_METADATA/PROJECTION_PARAMETERS> group </SST> compound <SST_Composite> (Latitude, Longitude, SST) (DIM_000) compound <SST_Dataset> (Latitude, Longitude, SST) (DIM_000) group </SST/GP_PARAM_INFO>

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HDF-EOS5 OpenDapHDF-EOS5 OpenDapUsing liboc-dap-0.0.2

In Alpha Version

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HDF-EOS5 OpenDap HDF-EOS5 OpenDap -- a sample script-- a sample script

url = "http://acdisc.gsfc.nasa.gov/opendap/HDF-EOS5/Aura_OMI_Level3/OMAEROe.003/2010/"

filename = url + "OMI-Aura_L3-OMAEROe_2010m0712_v003-2010m0714t203639.he5”

f = addfile(filename,"r”)

◦ print(f) vis_aerosol = f->SingleScatteringAlbedoPassedThresholdMean

◦ printVarSummary(vis_aerosol)

lat = f->Latitude

◦ printVarSummary(lat) lon = f->Longitude

◦ printVarSummary(lon)

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HDF-EOS5 OpenDap –sample plotHDF-EOS5 OpenDap –sample plot

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ConclusionConclusionHDF-EOS5 is already released◦5.2.0 in April, 2010◦5.2.1 in July, 2010

HDF5 will be released soon◦Being tested with lots of data◦In Beta Version

HDF-EOS5 OpenDap is on the way◦With limited test◦In Alpha Version

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Questions?Questions?

Thank You!

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Write HDF5 with NCLWrite HDF5 with NCLWrite HDF5 with Options:◦Compression

At File Level At Variable Level

◦Chunking At File Level At Variable Level

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Sample Script to Write HDF5Sample Script to Write HDF5

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