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The HDF Group

Easy Access of HDF data via
NCL/IDL/MATLAB
Kent Yang, Tong Qi, Ziying Li, Yi Wang, Shu
Zhang, Joe Lee
The H...
Motivation
• Many Heterogeneous NASA HDF data
products
• To visualize the data, different products need
to be handled diff...
Learning Curve of accessing HDF data

NCL

From the ESIP wiki page:
http://wiki.esipfed.org/index.php/Making_Science_Data_...
Motivation

September 28, 2010

HDF/HDF-EOS Workshop XIV

4

www.hdfgroup.org
How?

September 28, 2010

HDF/HDF-EOS Workshop XIV

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www.hdfgroup.org
The HDF Group

Basic Examples

September 28, 2010

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Introduction to NCL/IDL/MATLAB
• Interpreted languages
• Visualization, analysis and computation
• NCL

- Free package, de...
A simple NCL example
load "$NCARG_ROOT/lib/ncarg/nclex/gsun/gsn_code.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_c...
• Complete Code can be found under
http://hdfeos.org/software/ncl.php#ref_sec:ncl-hdfeos2-grid-1d-unabridged

September 28...
A simple IDL example
PRO AMSR_E_L2A_BrightnessTemperatures
FILE_NAME=
"AMSR_E_L2A_BrightnessTemperatures_V09_200206190029_...
A simple MATLAB example
• FILE_NAME='AMSR_E_L2A.hdf'
SWATH_NAME='Low_Res_Swath‘
file_id = hdfsw('open', FILE_NAME, 'rdonly...
• More information on the descriptions of these
examples
• Check hdfeos.org
• NCL: http://hdfeos.org/software/ncl.php
• ID...
Motivation

September 28, 2010

HDF/HDF-EOS Workshop XIV

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www.hdfgroup.org
More helpful
• A comprehensive NCL/IDL/MATLAB
example codes and plots for sample data
from most NASA Data centers:
GES DIS...
Where are these examples located?

• http://hdfeos.org/zoo/
• We welcome you to send us feedback on
these examples. You ca...
Common Issues for Tools
• MATLAB and IDL
- IDL
- For IDL 7.x and before, cannot add
color bar by using scripts
- MATLAB
- ...
Common Issues for Tools
• MATLAB and IDL
- HDF-EOS2 non-geographic projection Grids
- Need to provide additional latitude ...
Other Issues
• Different ways to store metadata in an HDF file
- Some HDF4 products don’t provide lat/lon
- Some HDF4 prod...
A Tip that you need to remember
• You can always use HDFView to quickly
examine any HDF files.

September 28, 2010

HDF/HD...
September 28, 2010

HDF/HDF-EOS Workshop XIV

20

www.hdfgroup.org
The HDF Group

Now we will walk through
examples for each NASA
data center

September 28, 2010

HDF/HDF-EOS Workshop XIV

...
The HDF Group

GES DISC

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GES DISC AIRS Swath
• Directly read the lat/lon and use the polar view
…
data=eos_file>radiances_L2_Standard_cloud_cleared...
GES DISC AIRS Swath

IDL

September 28, 2010

Matlab

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GES DISC AIRS Grid
• A typical global grid. Lat. and Lon. are provided.
…
%Reading Data from a Data Field
GRID_NAME='ascen...
GES DISC AIRS Grid

NCL

September 28, 2010

IDL

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GES DISC TRMM Swath
• The global view doesn’t show much
information; need a zoom view.

1B21_CSI.990906.10217.KORA.6_binDI...
GES DISC TRMM Swath

Matlab
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GES DISC TRMM Grid
• Grid, 3B43:
• Calculate lat/lon based on the formula
• Add “units”
http://disc.sci.gsfc.nasa.gov/addi...
GES DISC MERRA Grid
• A typical global grid
…
data=eos_file->PLE_EOSGRID(1,72,:,:) ; read specific subset of data
field
;
...
GES DISC TOMS Grid
…
;retrieve data
grid_id = EOS_GD_ATTACH(file_id, GRID_NAME)
status = EOS_GD_READFIELD(grid_id, DATAFIE...
The HDF Group

MODAPS
MODIS Level 1 Swath

September 28, 2010

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32

www.hdfgroup.org
MODAPS(LAADS) Swath

MYD021KM.A2002226.0000.005.200919322273

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33

www.hdfgro...
MODAPS(LAADS)
• MODIS Swath using dimension map
• It needs additional latitude and longitude files
provided by NASA
• Wher...
MODAPS(LAADS)
• Need to apply the scale and offset factor, need special formula
•

Normal: Data = scale* data + offset

Ma...
The HDF Group

NSIDC

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NSIDC Swath

Matlab
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www.hdfgroup.org
NSIDC Polar Sterographic Grid

NCL
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www.hdfgroup.org
The HDF Group

LP- DAAC

September 28, 2010

HDF/HDF-EOS Workshop XIV

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www.hdfgroup.org
LP-DAAC Sinusoidal Grid
• The lat/lon are calculated by the hdfeos2 dumper tool
http://hdfeos.org/software/eosdump.php

MO...
The HDF Group

PO. DAAC

September 28, 2010

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41

www.hdfgroup.org
PO.DAAC Geographic Grid
• Need to calculate the lat/lon based on the information provided
by the product document.

NCL

M...
The HDF Group

OBPG(Ocean Color)

September 28, 2010

HDF/HDF-EOS Workshop XIV

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OBPG SeaWiFS

Matlab
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MODISA Swath

Matlab
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www.hdfgroup.org
MODIST Grid

Matlab

September 28, 2010

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www.hdfgroup.org
The HDF Group

GHRC

September 28, 2010

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www.hdfgroup.org
GHRC Level 3 Grid

NCL

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The HDF Group

LaRC

September 28, 2010

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LaRC

• Special projections: Space Oblique Mercator
(SOM)
• Nested CERES Grid

September 28, 2010

HDF/HDF-EOS Workshop XI...
LaRC GOMACCS
Space Oblique Mercator(SOM) Grid

MISR_ELLIPSOID_GM_P017_O036105_DF_F03_0024_GOM_b64-72_Blue_RadianceRDQI.idl...
LaRC MISR SOM

MISR_AM1_AGP_P001_F01_24_PtElev.idl

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LaRC MOPITT

NCL

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LaRC_CERES cross-section
;Open file
FILE_NAME='CER_ZAVG_Aqua-FM4MODIS_Edition2B_007005.200503.hdf'
newFileID=HDF_SD_START(...
CERES Nested Grid
• http://eosweb.larc.nasa.gov/PRODOCS/ceres/
SRBAVG/Quality_Summaries/srbavg_ed2d/ne
stedgrid.html
• Suc...
LaRC_CERES

Hammer
Sinusoidal

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Limitations
• No tools can generate LAMAZ(Lambert
Azimuthal projection ) grid properly.
• No latitude and longitude files ...
Again
• Example codes and plots are under
http://hdfeos.org/zoo
• We welcome you to send us feedback on
these examples. Yo...
The HDF Group

Thank you !

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Acknowledgements
This work was supported by cooperative agreement
number NNX08AO77A from the National
Aeronautics and Spac...
The HDF Group

Questions/comments?

September 28, 2010

HDF/HDF-EOS Workshop XIV

61

www.hdfgroup.org
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Usage of NCL, IDL, and MATLAB to access NASA HDF4/HDF-EOS2/HDF-EOS5 data

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The HDF Group provides NCL/IDL/MATLAB example codes and plots for many NASA HDF-EOS2 and HDF4 products. These example codes and plots can be found under http://hdfeos.org/zoo. This slide addresses some common issues on using these tools to visualize NASA HDF-EOS2 and HDF4 products.

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  • The Earth Observing System Project Science Office -> eospso.gsfc.nasa.gov (Information about Earth Observing System)SDP Toolkit/HDF-EOS: http://newsroom.gsfc.nasa.gov/sdptoolkit/toolkit.html HDF Group website: http://hdfgroup.orgBut HDF-EOS Tools and Information Center http://hdfeos.org or http://hdfeos.net Screenshot of http://hdfeos.orgExplain two reasons for this work:We’ve done this work in the past few months.Some information of tools are out of date. Need to be updated.Requests for more information such as examples.
  • developed by the CISL at NCAR. It is an interpreted language designed for visualization and analysis of scientific data.
  • The Earth Observing System Project Science Office -> eospso.gsfc.nasa.gov (Information about Earth Observing System)SDP Toolkit/HDF-EOS: http://newsroom.gsfc.nasa.gov/sdptoolkit/toolkit.html HDF Group website: http://hdfgroup.orgBut HDF-EOS Tools and Information Center http://hdfeos.org or http://hdfeos.net Screenshot of http://hdfeos.orgExplain two reasons for this work:We’ve done this work in the past few months.Some information of tools are out of date. Need to be updated.Requests for more information such as examples.
  • In general, for all the following slides: You need to specify the tool name under the plot. The font should not be too small.Add another code section:Amplify data@lat2d=eos_file->Latitude_L2_Standard_cloud_cleared_radiance_product..Amplify:plot(3)=gsn_csm_contour_map_polar(xwks,data_3,res…)Replace the plot with channel 567
  • Plots will fly in
  • Add a zoom view
  • Add a code section for calculating the lat/lon.
  • IDL code and plot
  • MYD021KM.A2002226.0000.005.2009193222735_EV_1KM_Emissive.nclAlso add a global view if we have one.I already add global view, the zoom view will fly in
  • Provide the code section and circle the line that applies the scale offset.
  • Matlab
  • Add the code that reads the lat/lon.
  • Replace this with http://eoszoo.hdfgroup.uiuc.edu/zoo/OBPG/S1997247162631.L2_MLAC_OC_Rrs_412_zoom.idl.JPG
  • Add a MODIST grid Matlab plot.
  • NCL
  • Remove this one.
  • Provide the code section for lat/lon
  • Provide the code section on how this is plotted.
  • Transcript of "Usage of NCL, IDL, and MATLAB to access NASA HDF4/HDF-EOS2/HDF-EOS5 data"

    1. 1. The HDF Group Easy Access of HDF data via NCL/IDL/MATLAB Kent Yang, Tong Qi, Ziying Li, Yi Wang, Shu Zhang, Joe Lee The HDF Group September 28, 2010 HDF/HDF-EOS Workshop XIV 1 www.hdfgroup.org
    2. 2. Motivation • Many Heterogeneous NASA HDF data products • To visualize the data, different products need to be handled differently • Users need to spend extra time figuring out the solutions • Individual data centers have already provided data services for the data they distributed • Some end-users prefer to use their favorite tools to access HDF data September 28, 2010 HDF/HDF-EOS Workshop XIV 2 www.hdfgroup.org
    3. 3. Learning Curve of accessing HDF data NCL From the ESIP wiki page: http://wiki.esipfed.org/index.php/Making_Science_Data_Easier_to_Use_with_OPeNDAP Making Science Data Easier to Use with OPeNDAP September 28, 2010 HDF/HDF-EOS Workshop XIV 3 www.hdfgroup.org
    4. 4. Motivation September 28, 2010 HDF/HDF-EOS Workshop XIV 4 www.hdfgroup.org
    5. 5. How? September 28, 2010 HDF/HDF-EOS Workshop XIV 5 www.hdfgroup.org
    6. 6. The HDF Group Basic Examples September 28, 2010 HDF/HDF-EOS Workshop XIV 6 www.hdfgroup.org
    7. 7. Introduction to NCL/IDL/MATLAB • Interpreted languages • Visualization, analysis and computation • NCL - Free package, developed by NCAR - Support HDF-EOS2, HDF-EOS5 and HDF4 • IDL - Widely used by Earth Science Community - Support HDF-EOS2, HDF4 and HDF5 • MATLAB - Widely used by Computation and Engineering Communities - Support HDF-EOS2, HDF4 and HDF5 September 28, 2010 HDF/HDF-EOS Workshop XIV 7 www.hdfgroup.org
    8. 8. A simple NCL example load "$NCARG_ROOT/lib/ncarg/nclex/gsun/gsn_code.ncl" load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl" begin cdf_file = addfile("AMSR_E_L3_RainGrid_B05_200707.he2","r") rrland = cdf_file->RrLandRain_MonthlyRainTotal_GeoGrid(:,:) rrland@_FillValue = -1 resources = True xwks = gsn_open_wks("pdf","AE_RnGd.hdfeos2") plot = gsn_csm_contour_map_ce(xwks,rrland,resources) end September 28, 2010 HDF/HDF-EOS Workshop XIV 8 www.hdfgroup.org
    9. 9. • Complete Code can be found under http://hdfeos.org/software/ncl.php#ref_sec:ncl-hdfeos2-grid-1d-unabridged September 28, 2010 HDF/HDF-EOS Workshop XIV 9 www.hdfgroup.org
    10. 10. A simple IDL example PRO AMSR_E_L2A_BrightnessTemperatures FILE_NAME= "AMSR_E_L2A_BrightnessTemperatures_V09_200206190029_D.hdf“ SWATH_NAME='Low_Res_Swath' DATAFIELD_NAME='23.8H_Approx._Res.3_TB_(not-resampled)' file_id = EOS_SW_OPEN(FILE_NAME) swath_id = EOS_SW_ATTACH(file_id, SWATH_NAME) status = EOS_SW_READFIELD(swath_id, DATAFIELD_NAME, data) status = EOS_SW_READFIELD(swath_id, 'Longitude', lon) status = EOS_SW_READFIELD(swath_id, 'Latitude', lat) status = EOS_SW_DETACH(swath_id) status = EOS_SW_CLOSE(file_id) MAP_SET, /GRID, /CONTINENTS CONTOUR, data, lon, lat, /OVERPLOT, NLEVELS=20, /CELL_FILL END September 28, 2010 HDF/HDF-EOS Workshop XIV 10 www.hdfgroup.org
    11. 11. A simple MATLAB example • FILE_NAME='AMSR_E_L2A.hdf' SWATH_NAME='Low_Res_Swath‘ file_id = hdfsw('open', FILE_NAME, 'rdonly') swath_id = hdfsw('attach', file_id, SWATH_NAME) DATAFIELD_NAME='23.8H_Approx._Res.3_TB_(not-resampled)' [data, fail] = hdfsw('readfield', swath_id, DATAFIELD_NAME, [], [], []) [lon, status] = hdfsw('readfield', swath_id, 'Longitude', [], [], []) [lat, status] = hdfsw('readfield', swath_id, 'Latitude', [], [], []) hdfsw('detach', swath_id); hdfsw('close', file_id); contourf(lon,lat,data); September 28, 2010 HDF/HDF-EOS Workshop XIV 11 www.hdfgroup.org
    12. 12. • More information on the descriptions of these examples • Check hdfeos.org • NCL: http://hdfeos.org/software/ncl.php • IDL: http://hdfeos.org/examples/idl.php • MATLAB: http://hdfeos.org/examples/matlab.php September 28, 2010 HDF/HDF-EOS Workshop XIV 12 www.hdfgroup.org
    13. 13. Motivation September 28, 2010 HDF/HDF-EOS Workshop XIV 13 www.hdfgroup.org
    14. 14. More helpful • A comprehensive NCL/IDL/MATLAB example codes and plots for sample data from most NASA Data centers: GES DISC MODAPS(LAADS) NSIDC LP-DAAC P.O DAAC GHRC OBPG(Ocean Color) LaRC September 28, 2010 HDF/HDF-EOS Workshop XIV 14 www.hdfgroup.org
    15. 15. Where are these examples located? • http://hdfeos.org/zoo/ • We welcome you to send us feedback on these examples. You can use the HDF-EOS forum(http://hdfeos.org/forums) to share your comments or contact us at eoshelp@hdfgroup.org . September 28, 2010 HDF/HDF-EOS Workshop XIV 15 www.hdfgroup.org
    16. 16. Common Issues for Tools • MATLAB and IDL - IDL - For IDL 7.x and before, cannot add color bar by using scripts - MATLAB - For data array > 1MB, one needs to use 64-bit MATLAB to generate plots; Takes very long time. September 28, 2010 HDF/HDF-EOS Workshop XIV 16 www.hdfgroup.org
    17. 17. Common Issues for Tools • MATLAB and IDL - HDF-EOS2 non-geographic projection Grids - Need to provide additional latitude and longitude files - HDF-EOS2 geographic projection Grids - Need to obtain parameters to calculate latitude and longitude • All Tools - HDF-EOS2 Swaths with dimension maps - Need to provide additional latitude and longitude files September 28, 2010 HDF/HDF-EOS Workshop XIV 17 www.hdfgroup.org
    18. 18. Other Issues • Different ways to store metadata in an HDF file - Some HDF4 products don’t provide lat/lon - Some HDF4 products provide attributes to calculate lat/lon • Users not familiar with HDF4 and HDF-EOS2 file structures September 28, 2010 HDF/HDF-EOS Workshop XIV 18 www.hdfgroup.org
    19. 19. A Tip that you need to remember • You can always use HDFView to quickly examine any HDF files. September 28, 2010 HDF/HDF-EOS Workshop XIV 19 www.hdfgroup.org
    20. 20. September 28, 2010 HDF/HDF-EOS Workshop XIV 20 www.hdfgroup.org
    21. 21. The HDF Group Now we will walk through examples for each NASA data center September 28, 2010 HDF/HDF-EOS Workshop XIV 21 www.hdfgroup.org
    22. 22. The HDF Group GES DISC September 28, 2010 HDF/HDF-EOS Workshop XIV 22 www.hdfgroup.org
    23. 23. GES DISC AIRS Swath • Directly read the lat/lon and use the polar view … data=eos_file>radiances_L2_Standard_cloud_cleared_radiance_product(:,:,0) ; read specific subset of data field ; In order to read the radiances data field from the HDF-EOS2 file, the group ; under which the data field is placed must be appended to the data field in NCL. For more information, ; visit section 4.3.2 of http://hdfeos.org/software/ncl.php. data@lat2d=eos_file>Latitude_L2_Standard_cloud_cleared_radiance_product ; associate longitude and latitude data@lon2d=eos_file>Longitude_L2_Standard_cloud_cleared_radiance_product data@_FillValue=-9999 ; … res@gsnCenterString="radiances at Channel=567" plot(2)=gsn_csm_contour_map_polar(xwks,data_2,res) res@gsnCenterString="radiances at Channel=1339" plot(3)=gsn_csm_contour_map_polar(xwks,data_3,res) delete(plot) ; cleaning up resources used delete(data) NCL September 28, 2010 HDF/HDF-EOS Workshop XIV 23 www.hdfgroup.org
    24. 24. GES DISC AIRS Swath IDL September 28, 2010 Matlab HDF/HDF-EOS Workshop XIV 24 www.hdfgroup.org
    25. 25. GES DISC AIRS Grid • A typical global grid. Lat. and Lon. are provided. … %Reading Data from a Data Field GRID_NAME='ascending'; grid_id = hdfgd('attach', file_id, GRID_NAME); DATAFIELD_NAME='RelHumid_A'; [data1, fail] = hdfgd('readfield', grid_id, DATAFIELD_NAME, [], [], []); … %Reading Lat and Lon Data GRID_NAME='location'; grid_id = hdfgd('attach', file_id, GRID_NAME); %Reading Lat Data DATAFIELD_NAME='Latitude'; [lat, status] = hdfgd('readfield', grid_id, DATAFIELD_NAME, [], [], []); lat=double(lat); [fillvalue,status] = hdfgd('getfillvalue',grid_id, DATAFIELD_NAME); lat(lat==fillvalue) = NaN; %Reading Lon Data DATAFIELD_NAME='Longitude'; [lon, status] = hdfgd('readfield', grid_id, DATAFIELD_NAME, [], [], []); lon=double(lon); [fillvalue,status] = hdfgd('getfillvalue',grid_id, DATAFIELD_NAME); lon(lon==fillvalue) = NaN; … September 28, 2010 HDF/HDF-EOS Workshop XIV Matlab 25 www.hdfgroup.org
    26. 26. GES DISC AIRS Grid NCL September 28, 2010 IDL HDF/HDF-EOS Workshop XIV 26 www.hdfgroup.org
    27. 27. GES DISC TRMM Swath • The global view doesn’t show much information; need a zoom view. 1B21_CSI.990906.10217.KORA.6_binDIDHmean.idl September 28, 2010 HDF/HDF-EOS Workshop XIV 27 www.hdfgroup.org
    28. 28. GES DISC TRMM Swath Matlab September 28, 2010 HDF/HDF-EOS Workshop XIV 28 www.hdfgroup.org
    29. 29. GES DISC TRMM Grid • Grid, 3B43: • Calculate lat/lon based on the formula • Add “units” http://disc.sci.gsfc.nasa.gov/additional/faq/precipitation_faq.shtml#lat_lon NCL September 28, 2010 HDF/HDF-EOS Workshop XIV 29 www.hdfgroup.org
    30. 30. GES DISC MERRA Grid • A typical global grid … data=eos_file->PLE_EOSGRID(1,72,:,:) ; read specific subset of data field ; ; In order to read the PLE data field from the HDF-EOS2 file, the group ; under which the data field is placed must be appended to the data field in NCL. For more information, ; visit section 4.3.2 of http://hdfeos.org/software/ncl.php. data@lon1d=eos_file->XDim_EOSGRID ; associate longitude and latitude data@lat1d=eos_file->YDim_EOSGRID ; here, since the XDim/YDim arrays are 1-D, we use lon1d instead of lon2d data@units="Pa" data@long_name="Edge pressures" … data_4=eos_file->PLE_EOSGRID(7,70,:,:) ; read specific subset of data field data_4@lon1d=eos_file->XDim_EOSGRID ; associate longitude and latitude data_4@lat1d=eos_file->YDim_EOSGRID data_4@units="Pa" data_4@long_name="Edge pressures“ … res@gsnCenterString="PLE at TIME=1, Height=72" plot(0)=gsn_csm_contour_map_ce(xwks,data,res) … September 28, 2010 HDF/HDF-EOS Workshop XIV NCL 30 www.hdfgroup.org
    31. 31. GES DISC TOMS Grid … ;retrieve data grid_id = EOS_GD_ATTACH(file_id, GRID_NAME) status = EOS_GD_READFIELD(grid_id, DATAFIELD_NAME, data) ;close file status = EOS_GD_DETACH(grid_id) status = EOS_GD_CLOSE(file_id) … ;retrieve lat ;field name should be defined as "YDim:TOMS Level 3" instead of "YDim:TOMS Level 3 (dimension)" DATAFIELD_NAME="YDim:TOMS Level 3" index=HDF_SD_NAMETOINDEX(newFileID,DATAFIELD_NAME) thisSdsID=HDF_SD_SELECT(newFileID, index) HDF_SD_GETDATA, thisSdsID, lat ;retrieve lon ;field name should be defined as "XDim:TOMS Level 3" instead of "XDim:TOMS Level 3 (dimension)" DATAFIELD_NAME="XDim:TOMS Level 3" index=HDF_SD_NAMETOINDEX(newFileID,DATAFIELD_NAME) … CONTOUR, BYTSCL(data, /NAN), lon, lat, /OVERPLOT, /FILL, C_Colors =Indgen(levels)+3, Background=1, NLEVELS=levels, Color=Black MAP_GRID, /BOX_AXES, COLOR=255 MAP_CONTINENTS, COLOR=255 … TOMS-EP_L3-TOMSEPL3_2000m0101_v8_Ozone.idl September 28, 2010 HDF/HDF-EOS Workshop XIV 31 www.hdfgroup.org
    32. 32. The HDF Group MODAPS MODIS Level 1 Swath September 28, 2010 HDF/HDF-EOS Workshop XIV 32 www.hdfgroup.org
    33. 33. MODAPS(LAADS) Swath MYD021KM.A2002226.0000.005.200919322273 September 28, 2010 HDF/HDF-EOS Workshop XIV 33 www.hdfgroup.org
    34. 34. MODAPS(LAADS) • MODIS Swath using dimension map • It needs additional latitude and longitude files provided by NASA • Where to obtain the corresponding latitude and longitude files? -ftp://ladsweb.nascom.nasa.gov/allData/5/MYD03 Or ftp://ladsweb.nascom.nasa.gov/allData/5/MOD03 MODIS Swath with dimension map September 28, 2010 HDF/HDF-EOS Workshop XIV 34 www.hdfgroup.org
    35. 35. MODAPS(LAADS) • Need to apply the scale and offset factor, need special formula • Normal: Data = scale* data + offset Matlab September 28, 2010 HDF/HDF-EOS Workshop XIV 35 www.hdfgroup.org
    36. 36. The HDF Group NSIDC September 28, 2010 HDF/HDF-EOS Workshop XIV 36 www.hdfgroup.org
    37. 37. NSIDC Swath Matlab September 28, 2010 HDF/HDF-EOS Workshop XIV 37 www.hdfgroup.org
    38. 38. NSIDC Polar Sterographic Grid NCL September 28, 2010 HDF/HDF-EOS Workshop XIV 38 www.hdfgroup.org
    39. 39. The HDF Group LP- DAAC September 28, 2010 HDF/HDF-EOS Workshop XIV 39 www.hdfgroup.org
    40. 40. LP-DAAC Sinusoidal Grid • The lat/lon are calculated by the hdfeos2 dumper tool http://hdfeos.org/software/eosdump.php MOD09GA.A2007268.h10v08.005.2007272184810_sur_refl_b01_1.idl September 28, 2010 HDF/HDF-EOS Workshop XIV 40 www.hdfgroup.org
    41. 41. The HDF Group PO. DAAC September 28, 2010 HDF/HDF-EOS Workshop XIV 41 www.hdfgroup.org
    42. 42. PO.DAAC Geographic Grid • Need to calculate the lat/lon based on the information provided by the product document. NCL Matlab September 28, 2010 HDF/HDF-EOS Workshop XIV 42 www.hdfgroup.org
    43. 43. The HDF Group OBPG(Ocean Color) September 28, 2010 HDF/HDF-EOS Workshop XIV 43 www.hdfgroup.org
    44. 44. OBPG SeaWiFS Matlab September 28, 2010 HDF/HDF-EOS Workshop XIV 44 www.hdfgroup.org
    45. 45. MODISA Swath Matlab September 28, 2010 HDF/HDF-EOS Workshop XIV 45 www.hdfgroup.org
    46. 46. MODIST Grid Matlab September 28, 2010 HDF/HDF-EOS Workshop XIV 46 www.hdfgroup.org
    47. 47. The HDF Group GHRC September 28, 2010 HDF/HDF-EOS Workshop XIV 47 www.hdfgroup.org
    48. 48. GHRC Level 3 Grid NCL September 28, 2010 HDF/HDF-EOS Workshop XIV 48 www.hdfgroup.org
    49. 49. The HDF Group LaRC September 28, 2010 HDF/HDF-EOS Workshop XIV 49 www.hdfgroup.org
    50. 50. LaRC • Special projections: Space Oblique Mercator (SOM) • Nested CERES Grid September 28, 2010 HDF/HDF-EOS Workshop XIV 50 www.hdfgroup.org
    51. 51. LaRC GOMACCS Space Oblique Mercator(SOM) Grid MISR_ELLIPSOID_GM_P017_O036105_DF_F03_0024_GOM_b64-72_Blue_RadianceRDQI.idl September 28, 2010 HDF/HDF-EOS Workshop XIV 51 www.hdfgroup.org
    52. 52. LaRC MISR SOM MISR_AM1_AGP_P001_F01_24_PtElev.idl September 28, 2010 HDF/HDF-EOS Workshop XIV 52 www.hdfgroup.org
    53. 53. LaRC MOPITT NCL September 28, 2010 HDF/HDF-EOS Workshop XIV 53 www.hdfgroup.org
    54. 54. LaRC_CERES cross-section ;Open file FILE_NAME='CER_ZAVG_Aqua-FM4MODIS_Edition2B_007005.200503.hdf' newFileID=HDF_SD_START(FILE_NAME, /READ) ;Define datafield DATAFIELD_NAME='Ice Particle Diameter' index=HDF_SD_NAMETOINDEX(newFileID,DATAFIELD_NAME) ;Retrieve data thisSdsID=HDF_SD_SELECT(newFileID, index) HDF_SD_GETDATA, thisSdsID, data … ;generate lat lat=FINDGEN(180)*(-1)+89.5 ;generate ngmt ngmt=FINDGEN(8)*1+1 … ; Start off generating the plot levels = 250 device, decomposed=0 LoadCT, 33, Ncolors=levels, Bottom=3 WINDOW, title='Ice Particle Diameter at Stats=0'+' '+'units:'+units, XSIZE=800 CONTOUR, data2D, ngmt, lat, /Fill, C_Colors=Indgen(levels)+3, Backgro und=1, NLEVELS=levels, Color=Black, XTITLE='Monthly 3-hourly GMT time increments', YTITLE='latitude',POSITION=[0.1, 0.1, 0.82, 0.95] … CER_ZAVG_Aqua-FM4-MODIS_Edition2B_007005.200503.idl September 28, 2010 HDF/HDF-EOS Workshop XIV 54 www.hdfgroup.org
    55. 55. CERES Nested Grid • http://eosweb.larc.nasa.gov/PRODOCS/ceres/ SRBAVG/Quality_Summaries/srbavg_ed2d/ne stedgrid.html • Such projection is not supported. We have to emulate the projection. September 28, 2010 HDF/HDF-EOS Workshop XIV 55 www.hdfgroup.org
    56. 56. LaRC_CERES Hammer Sinusoidal September 28, 2010 HDF/HDF-EOS Workshop XIV 56 www.hdfgroup.org
    57. 57. Limitations • No tools can generate LAMAZ(Lambert Azimuthal projection ) grid properly. • No latitude and longitude files can be found for 250 meter and 500 meter MOD and MYD swaths using dimension maps distributed by MODAPS. • Some tools don’t support all projections. September 28, 2010 HDF/HDF-EOS Workshop XIV 57 www.hdfgroup.org
    58. 58. Again • Example codes and plots are under http://hdfeos.org/zoo • We welcome you to send us feedback on these examples. You can use the HDF-EOS forum(http://hdfeos.org/forums) to share your comments or contact us at eoshelp@hdfgroup.org . September 28, 2010 HDF/HDF-EOS Workshop XIV 58 www.hdfgroup.org
    59. 59. The HDF Group Thank you ! September 28, 2010 HDF/HDF-EOS Workshop XIV 59 www.hdfgroup.org
    60. 60. Acknowledgements This work was supported by cooperative agreement number NNX08AO77A from the National Aeronautics and Space Administration (NASA). Any opinions, findings, conclusions, or recommendations expressed in this material are those of the author[s] and do not necessarily reflect the views of the National Aeronautics and Space Administration. September 28, 2010 HDF/HDF-EOS Workshop XIV 60 www.hdfgroup.org
    61. 61. The HDF Group Questions/comments? September 28, 2010 HDF/HDF-EOS Workshop XIV 61 www.hdfgroup.org
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