[gradsusr] Problem in opening MODIS HDF files

Ehsan Erfani e.erfani81 at gmail.com
Sat Oct 13 19:54:43 EDT 2012


Hi again,

I attached an hdf file with a ctl (I downloaded the data from Giovanni
website and I wrote the ctl). This time, the Grads can open the data, but
when I write the command: d Angstrom_Exponent_Land_QA_Mean, This error
message appears:
Syntax Error:  Invalid Operand
  'angstrom_exponent' not a variable or function name
  Error ocurred at column 1
DISPLAY error:  Invalid expression
  Expression = angstrom_exponent_land_qa_mean

But, I am sure the name of variable is true. I checked it by HDFView and
this is the information from HDFView:
Angstrom_Exponent_Land_QA_Mean (720, 2)
    32-bit floating-point,    180 x 360
    Number of attributes = 18
        _FillValue = -9999.0
        QA_Useful_Flag_Bit = 0
        Quality_Assurance_Data_Set = Quality_Assurance_Land
        scale_factor = 1.0
        QA_Value_Start_Bit = 1
        add_offset = 0.0
        long_name = Angstrom exponent (Land) for 0.47 and 0.66 microns:
Level-2 QA Weighted Mean
        Statistic_Type = Simple
        units = unitless
        QA_Byte = 0
        Aggregation_Data_Set = None
        valid_range = -500,5000
        Included_Level_2_Nighttime_Data = False
        Derived_From_Level_2_Data_Set = Angstrom_Exponent_Land
        QA_Value_Num_Bits = 3
        Level_2_Pixel_Values_Read_As = Real
        structureType = Grid
        unitsCategory = exponent

Hope these help to solve the problems. I appreciate all your consideration
and help.

Best regards,
Ehsan

On Sat, Oct 13, 2012 at 1:26 AM, Ehsan Erfani <e.erfani81 at gmail.com> wrote:

> 1- I used grads-2.0.a3.oga.1.win32_superpack (GrADS OPenNDAP). Also, I
> tried grads-2.0.1.oga.1-win32_superpack.
> 2- Both of them are opengrads and run in windows.
> 3- First, I want to open hdf data without ctl (I have a lot of data and
> they do not have similar variables). So, I consider using sdfopen to open
> the files.
>
> 4- By using sdfopen, I received these error message for the above grads
> versions, respectively:
>
>
> "gradsdf : SDF file has no discernable X coordinate."
>
> "gadsdf: SDF file has no discernable X coordinate.
>  To open this file with GrADS, use a descriptor file with an XDEF entry."
>
> 5- I used MODIS hdf files. A typical name of the files can be
> "MOD08_D3.A2011152.051.2011153120457.hdf". I wanted to plot 550 nm AOD and
> deep blue AOD. These data are typical satellite data from terra or aqua.
> I do not have access to linux to provide ncdump data. Anyway, the message
> would be very long and I write some first lines (containing the dimension
> and grid data) from  the HDF Import Tool and write the full message in the
> end:
> Name: MERRA200.prod.assim.tavg1_2d_lnd_Nx.20000601.hdf HDFEOSVersion:
> HDFEOS_V2.14 StructMetadata.0: GROUP=SwathStructure
> END_GROUP=SwathStructure GROUP=GridStructure     GROUP=GRID_1
> GridName="EOSGRID"         XDim=540         YDim=361
> UpperLeftPointMtrs=(-180000000.000000,90000000.000000)
> LowerRightMtrs=(180000000.000000,-90000000.000000)
> Projection=GCTP_GEO         GridOrigin=HDFE_GD_LL
> GROUP=Dimension             OBJECT=Dimension_1
> DimensionName="TIME"                 Size=24
> END_OBJECT=Dimension_1         END_GROUP=Dimension
> GROUP=DataField             OBJECT=DataField_1
> DataFieldName="GRN"                 DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim") 3- I used sdfopen command to open them.
>
> Final word:
> I know that the problem can be due to the dimension, however the dimension
> is defined in the data by XDim and YDim, Time.  I wonder does anyone
> successfully use GrADS to open hdf files by sdfopen command. Is a certain
> version of GrADS recommended to do this?
>
> Thank you in advance,
> Ehsan
>
>
> On Fri, Oct 12, 2012 at 10:53 AM, Jennifer Adams <jma at cola.iges.org>wrote:
>
>> Your post is missing the following information:
>> 1. The version of GrADS you are running
>> 2. What operating system you're running it on
>> 3. The contents of your ctl file
>> 4. The error message you get when you try to open your ctl file
>> 5. More information about the grid in your MODIS file, especially the
>> output from ncdump (which is often enabled to handle HDF files)
>> Nobody can help until you provide these things.
>> --Jennifer
>>
>>
>>
>
> Name: MERRA200.prod.assim.tavg1_2d_lnd_Nx.20000601.hdf HDFEOSVersion:
> HDFEOS_V2.14 StructMetadata.0: GROUP=SwathStructure
> END_GROUP=SwathStructure GROUP=GridStructure     GROUP=GRID_1
> GridName="EOSGRID"         XDim=540         YDim=361
> UpperLeftPointMtrs=(-180000000.000000,90000000.000000)
> LowerRightMtrs=(180000000.000000,-90000000.000000)
> Projection=GCTP_GEO         GridOrigin=HDFE_GD_LL
> GROUP=Dimension             OBJECT=Dimension_1
> DimensionName="TIME"                 Size=24
> END_OBJECT=Dimension_1         END_GROUP=Dimension
> GROUP=DataField             OBJECT=DataField_1
> DataFieldName="GRN"                 DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_1             OBJECT=DataField_2
> DataFieldName="LAI"                 DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_2             OBJECT=DataField_3
> DataFieldName="GWETROOT"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_3             OBJECT=DataField_4
> DataFieldName="GWETTOP"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_4             OBJECT=DataField_5
> DataFieldName="TPSNOW"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_5             OBJECT=DataField_6
> DataFieldName="TUNST"                 DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_6             OBJECT=DataField_7
> DataFieldName="TSAT"                 DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_7             OBJECT=DataField_8
> DataFieldName="TWLT"                 DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_8             OBJECT=DataField_9
> DataFieldName="PRECSNO"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_9             OBJECT=DataField_10
> DataFieldName="PRECTOT"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_10             OBJECT=DataField_11
> DataFieldName="SNOMAS"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_11             OBJECT=DataField_12
> DataFieldName="SNODP"                 DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_12             OBJECT=DataField_13
> DataFieldName="EVPSOIL"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_13             OBJECT=DataField_14
> DataFieldName="EVPTRNS"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_14             OBJECT=DataField_15
> DataFieldName="EVPINTR"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_15             OBJECT=DataField_16
> DataFieldName="EVPSBLN"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_16             OBJECT=DataField_17
> DataFieldName="RUNOFF"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_17             OBJECT=DataField_18
> DataFieldName="BASEFLOW"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_18             OBJECT=DataField_19
> DataFieldName="SMLAND"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_19             OBJECT=DataField_20
> DataFieldName="FRUNST"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_20             OBJECT=DataField_21
> DataFieldName="FRSAT"                 DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_21             OBJECT=DataField_22
> DataFieldName="FRSNO"                 DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_22             OBJECT=DataField_23
> DataFieldName="FRWLT"                 DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_23             OBJECT=DataField_24
> DataFieldName="PARDF"                 DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_24             OBJECT=DataField_25
> DataFieldName="PARDR"                 DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_25             OBJECT=DataField_26
> DataFieldName="SHLAND"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_26             OBJECT=DataField_27
> DataFieldName="LHLAND"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_27             OBJECT=DataField_28
> DataFieldName="EVLAND"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_28             OBJECT=DataField_29
> DataFieldName="LWLAND"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_29             OBJECT=DataField_30
> DataFieldName="SWLAND"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_30             OBJECT=DataField_31
> DataFieldName="GHLAND"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_31             OBJECT=DataField_32
> DataFieldName="TWLAND"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_32             OBJECT=DataField_33
> DataFieldName="TELAND"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_33             OBJECT=DataField_34
> DataFieldName="WCHANGE"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_34             OBJECT=DataField_35
> DataFieldName="ECHANGE"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_35             OBJECT=DataField_36
> DataFieldName="SPLAND"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_36             OBJECT=DataField_37
> DataFieldName="SPWATR"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_37             OBJECT=DataField_38
> DataFieldName="SPSNOW"
> DataType=DFNT_FLOAT32
> DimList=("TIME","YDim","XDim")
> END_OBJECT=DataField_38             OBJECT=DataField_39
> DataFieldName="XDim"                 DataType=DFNT_FLOAT64
> DimList=("XDim")             END_OBJECT=DataField_39
> OBJECT=DataField_40                 DataFieldName="YDim"
> DataType=DFNT_FLOAT64                 DimList=("YDim")
> END_OBJECT=DataField_40             OBJECT=DataField_41
> DataFieldName="Time"                 DataType=DFNT_FLOAT64
> DimList=("TIME")             END_OBJECT=DataField_41
> END_GROUP=DataField         GROUP=MergedFields
> END_GROUP=MergedFields     END_GROUP=GRID_1 END_GROUP=GridStructure
> GROUP=PointStructure END_GROUP=PointStructure END
>
>> On Oct 11, 2012, at 9:53 PM, Ehsan Erfani wrote:
>>
>> Hello,
>>
>> I cannot open MODIS (Moderate Resolution Imaging Spectroradiometer) HDF
>> files by grads. I receive this message when I use the sdfopen:
>> "gradsdf : SDF file has no discernable X coordinate."
>>
>> I tried to open by xdfopen without any success. Also, I made a ctl but
>> again it did not help. I appreciate it if you let me know how to open hdf
>> files by GrADS. Thank you.
>>
>> Best regards,
>> Ehsan _______________________________________________
>> gradsusr mailing list
>> gradsusr at gradsusr.org
>> http://gradsusr.org/mailman/listinfo/gradsusr
>>
>>
>>  --
>> Jennifer M. Adams
>> IGES/COLA
>> 4041 Powder Mill Road, Suite 302
>> Calverton, MD 20705
>> jma at cola.iges.org
>>
>>
>>
>>
>> _______________________________________________
>> gradsusr mailing list
>> gradsusr at gradsusr.org
>> http://gradsusr.org/mailman/listinfo/gradsusr
>>
>>
>
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