[ncl-talk] hdf confusion

[Michael Notaro]

Sorry for the ignorant question but I am having trouble figuring out

how to properly retrieve the land-lake-ocean mask off this MODIS hdf file.

If I ncl_filedump *hdf, it shows the variable as ushort.  If I ncl_filedump *hdf.hdfeos,

it shows the variable as short.  Which should I use in addfile and how do I

retrieve the values of 001=land, 000=ocean, etc?

Michael



ncl_filedump h10v04_yellowstone/MOD13Q1.A2012001.h10v04.006.2015236172021.hdf.hdfeos



    short 250m_16_days_VI_Quality_MODIS_Grid_16DAY_250m_500m_VI ( YDim_MODIS_Grid_16DAY_250m_500m_VI, XDim_MODIS_Grid_16DAY_250m_500m_VI )

         coordinates : GridLat_MODIS_Grid_16DAY_250m_500m_VI, GridLon_MODIS_Grid_16DAY_250m_500m_VI

         hdfeos_name : 250m 16 days VI Quality

         projection : Sinusoidal

         unsigned : True

         Legend :

Bit Fields Description (Right to Left):

[0-1] : MODLAND_QA [2 bit range]

00: VI produced, good quality

01: VI produced, but check other QA

10: Pixel produced, but most probably cloudy

11: Pixel not produced due to other reasons than clouds

[2-5] : VI usefulness [4 bit range]

0000: Highest quality

0001: Lower quality

0010..1010: Decreasing quality

1100: Lowest quality

1101: Quality so low that it is not useful

1110: L1B data faulty

1111: Not useful for any other reason/not processed

[6-7] : Aerosol quantity [2 bit range]

00: Climatology

01: Low

10: Average

11: High (11)

[8] : Adjacent cloud detected; [1 bit range]

1: Yes

0: No

[9] : Atmosphere BRDF correction performed [1 bit range]

1: Yes

0: No

[10] : Mixed clouds  [1 bit range]

1: Yes

0: No

[11-13] : Land/Water Flag [3 bit range]

000: Shallow ocean

001: Land (Nothing else but land)

010: Ocean coastlines and lake shorelines

011: Shallow inland water

100: Ephemeral water

101: Deep inland water

110: Moderate or continental ocean

111: Deep ocean

[14] : Possible snow/ice [1 bit range]

1: Yes

0: No

[15] : Possible shadow [1 bit range]

1: Yes

0: No

         _FillValue : -1

         valid_range : ( 0, -2 )

         units : bit field

         long_name : 250m 16 days VI Quality


ncl_filedump h10v04_yellowstone/MOD13Q1.A2012001.h10v04.006.2015236172021.hdf


      ushort 250m_16_days_VI_Quality ( YDim_MODIS_Grid_16DAY_250m_500m_VI, XDim_MODIS_Grid_16DAY_250m_500m_VI )

         long_name : 250m 16 days VI Quality

         units : bit field

         valid_range : ( 0, 65534 )

         _FillValue : 65535

         Legend :

Bit Fields Description (Right to Left):

[0-1] : MODLAND_QA [2 bit range]

00: VI produced, good quality

01: VI produced, but check other QA

10: Pixel produced, but most probably cloudy

11: Pixel not produced due to other reasons than clouds

[2-5] : VI usefulness [4 bit range]

0000: Highest quality

0001: Lower quality

0010..1010: Decreasing quality

1100: Lowest quality

1101: Quality so low that it is not useful

1110: L1B data faulty

1111: Not useful for any other reason/not processed

[6-7] : Aerosol quantity [2 bit range]

00: Climatology

01: Low

10: Average

11: High (11)

[8] : Adjacent cloud detected; [1 bit range]

1: Yes

0: No

[9] : Atmosphere BRDF correction performed [1 bit range]

1: Yes

0: No

[10] : Mixed clouds  [1 bit range]

1: Yes

0: No

[11-13] : Land/Water Flag [3 bit range]

000: Shallow ocean

001: Land (Nothing else but land)

010: Ocean coastlines and lake shorelines

011: Shallow inland water

100: Ephemeral water

101: Deep inland water

110: Moderate or continental ocean

111: Deep ocean

[14] : Possible snow/ice [1 bit range]

1: Yes

0: No

[15] : Possible shadow [1 bit range]

1: Yes

0: No

         hdf_name : 250m 16 days VI Quality



Michael Notaro
Associate Director
Nelson Institute Center for Climatic Research
University of Wisconsin-Madison
Phone: (608) 261-1503
Email: mnotaro at wisc.edu
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20170613/5f1d1212/attachment.html