[gradsusr] Problem in opening MODIS HDF files
Jennifer Adams
jma at cola.iges.org
Sun Oct 14 07:57:24 EDT 2012
> Angstrom_Exponent_Land_QA_Mean=>AELQA_Mean 0 1, 1, 0, 0 Surface pressure [hPa]
Use
Angstrom_Exponent_Land_QA_Mean=>awlqa_mean 0 1, 1, 0, 0 Surface pressure [hPa]
GrADS doesn't like uppercase letters in the aliased variable name.
--Jennifer
On Oct 13, 2012, at 11:31 PM, Ehsan Erfani wrote:
> Thank you Jim,
>
> But when I abbreviate the name of variable as:
>
> AELQA_Mean 0 1, 1, 0, 0 Surface pressure [hPa]
>
> I receive this errror message:
>
> Error: Variable aelqa_mean not in HDF-SDS file
> Data Request Error: Error for variable 'aelqa_mean'
> Error ocurred at column 1
> DISPLAY error: Invalid expression
> Expression = aelqa_mean
>
>
> Any idea?
>
> Thank you in advance,
> Ehsan
>
>
>
> On Sat, Oct 13, 2012 at 7:46 PM, James T. Potemra <jimp at hawaii.edu> wrote:
> Ehsan:
>
> I think there is a character limit on the variable name. So, you have
> a variable called "Angstrom_Exponent_Land_QA_Mean", but GrADS
> is looking for "angstrom_expone". Instead, you can map the variable
> to something shorter (see http://www.iges.org/grads/gadoc/gadocindex.html),
> e.g., in your ctl file:
>
> Angstrom_Exponent_Land_QA_Mean=>AELQA_Mean 0 1, 1, 0, 0 Surface pressure [hPa]
>
> then open and display "aelqa_mean", or whatever you call it.
>
> Jim
>
>
> On 10/13/12 1:54 PM, Ehsan Erfani wrote:
>> 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
>>
>>
>>
>>
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>>
>>
>>
>>
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>
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--
Jennifer M. Adams
IGES/COLA
4041 Powder Mill Road, Suite 302
Calverton, MD 20705
jma at cola.iges.org
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