Re: MODIS HDF

On 8/30/11 12:14 PM, Dennis Shea wrote:
>
>
> npp!0="nlat"
> npp!1="nlon"
> ;;npp@lat2d=lat2d ; no ... only for graphics
> ;;npp@lon2d=lon2d ; no
> npp@coordinates="lat2d lon2d"
> npp@projection="sinusoidal"

       lat2d!0 = "nlat"
       lat2d!1 = "nlon"
       lon2d!0 = "nlat"
       lon2d!1 = "nlon"

>
> printVarSummary(npp)
>
> system("/bin/rm -f test.nc")
> out=addfile("test.nc","c")
> out->npp=npp
> out->lat2d=lat2d
> out->lon2d=lon2d
>
>
> On 8/30/11 12:05 PM, Michael Notaro wrote:
>> Thanks Dennis. Using hdfeof helps a lot and gives me the lats/lons now.
>>
>> Seems I am having another problem. After I read the hdfeos and retrieve
>> the lats/lons and data, I tried writing it to a file and always get segmentation fault.
>> What am I doing wrong?
>>
>>
>>
>>
>>
>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/shea_util.ncl"
>> begin
>>
>> ; 1km annual npp modis on 1200x1200 tiles
>>
>> a=addfile("/Users/notaro/downloads/Y2000/MOD17A3.A2000366.h11v11.305.2009342143541.hdf.hdfeos","r")
>>
>> lat2d=a->GridLat_MOD_Grid_MOD17A3
>> lon2d=a->GridLon_MOD_Grid_MOD17A3
>>
>> npp=short2flt(a->Npp_1km_MOD_Grid_MOD17A3)
>>
>> npp!0="lat2d"
>> npp!1="lon2d"
>> npp@lat2d=lat2d
>> npp@lon2d=lon2d
>> npp@coordinates="lat2d lon2d"
>> npp@projection="sinusoidal"
>>
>> printVarSummary(npp)
>>
>> out=addfile("test.nc","c")
>> out->npp=npp
>> out->lat2d=lat2d
>> out->lon2d=lon2d
>>
>> end
>>
>>
>>
>>
>>
>>
>>
>> Variable: npp
>> Type: float
>> Total Size: 5760000 bytes
>> 1440000 values
>> Number of Dimensions: 2
>> Dimensions and sizes: [lat2d | 1200] x [lon2d | 1200]
>> Coordinates:
>> Number Of Attributes: 7
>> lon2d : <ARRAY of 1440000 elements>
>> lat2d : <ARRAY of 1440000 elements>
>> _FillValue : 1e+20
>> coordinates : lat2d lon2d
>> hdfeos_name : Npp_1km
>> projection : sinusoidal
>> unsigned : True
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> On Aug 30, 2011, at 12:44 PM, Dennis Shea wrote:
>>
>>> Mike
>>>
>>> [1]
>>> %> ncl_filedump MOD17A3.A2010365.h00v08.305.2011029145245.hdf
>>>
>>> yields
>>>
>>> Variable: f
>>> Type: file
>>> filename: MOD17A3.A2010365.h00v08.305.2011029145245
>>> path: MOD17A3.A2010365.h00v08.305.2011029145245.hdf
>>> file global attributes:
>>> HDFEOSVersion : HDFEOS_V2.16
>>> StructMetadata_0 : GROUP=SwathStructure
>>> END_GROUP=SwathStructure
>>> GROUP=GridStructure
>>> GROUP=GRID_1
>>> GridName="MOD_Grid_MOD17A3"
>>> XDim=1200
>>> YDim=1200
>>> UpperLeftPointMtrs=(-20015109.354000,1111950.519667)
>>> LowerRightMtrs=(-18903158.834333,0.000000)
>>> Projection=GCTP_SNSOID
>>> [SNIP]
>>>
>>> [2]
>>> If you append the '.hdfeos' suffix, you will get that lat/lon values.
>>>
>>> %> ncl_filedump MOD17A3.A2010365.h00v08.305.2011029145245.hdf.hdfeos
>>>
>>> Variable: f
>>> Type: file
>>> filename: MOD17A3.A2010365.h00v08.305.2011029145245.hdf
>>> path: MOD17A3.A2010365.h00v08.305.2011029145245.hdf
>>> file global attributes:
>>> dimensions:
>>> YDim_MOD_Grid_MOD17A3 = 1200
>>> XDim_MOD_Grid_MOD17A3 = 1200
>>> variables:
>>> double GridLat_MOD_Grid_MOD17A3 ( YDim_MOD_Grid_MOD17A3,
>>> XDim_MOD_Grid_MOD17A3 )
>>> projection : (null)
>>> corners : ( 9.995833332438675, 9.995833332438675,
>>> 0.004166666666293064, 0.004166666666293064 )
>>> long_name : latitude
>>> units : degrees_north
>>>
>>> double GridLon_MOD_Grid_MOD17A3 ( YDim_MOD_Grid_MOD17A3,
>>> XDim_MOD_Grid_MOD17A3 )
>>> projection : (null)
>>> corners : ( 177.2297839752788, -172.6245418649626,
>>> -170.00416710093, -179.9958337931229 )
>>> long_name : longitude
>>> units : degrees_east
>>> [snip]
>>>
>>> [3] Use the hdfeos suffix. The names are different than using 'just' hdf
>>> however NCL does provide the georeferenced data coordinates.
>>>
>>>
>>> [4] You might look at:
>>>
>>> http://www.ncl.ucar.edu/Applications/binning.shtml
>>>
>>> Good luck
>>> D
>>>
>>>
>>>
>>>
>>> On 8/30/11 11:23 AM, Michael Notaro wrote:
>>>> I am trying to work with MODIS HDF data of the land variable 1-km annual NPP (net primary productivity).
>>>>
>>>> ftp://ftp.ntsg.umt.edu/pub/MODIS/Mirror/MOD17_Science_2010/MOD17A3/
>>>>
>>>> Each file is on a separate tile. I put the info below on a sample file's
>>>> info on the variable Npp_1km and the 1200x1200 grid and bounding rectangle.
>>>>
>>>> It is my understanding that I should grab the rectangles that overlap my study region,
>>>> which is Wisconsin. I think 4 of them overlap it.
>>>>
>>>> I can read in the data with addfile (or use ncl_convert2nc). But I am not sure
>>>> how to retrieve the proper lats/lons to plot the data correctly. I used short2flt also
>>>> when reading it. I am guessing that the data grid must not be a normal rectangle but
>>>> stretched as the satellite moves, since the range of the lats is 10 degrees but the
>>>> range of the lons is 60 degrees.
>>>>
>>>> Any suggestions on how to plot this in NCL is appreciated.
>>>>
>>>> Michael
>>>>
>>>>
>>>> YDim_MOD_Grid_MOD17A3 = 1200 ;
>>>> XDim_MOD_Grid_MOD17A3 = 1200 ;
>>>>
>>>> short Npp_1km(YDim_MOD_Grid_MOD17A3, XDim_MOD_Grid_MOD17A3) ;
>>>> Npp_1km:hdf_name = "Npp_1km" ;
>>>> Npp_1km:units = "kg_C/m^2" ;
>>>> Npp_1km:long_name = "MOD17A3 NPP--MODIS Gridded 1KM Annual Net Primary Productivity (NPP)" ;
>>>> Npp_1km:_FillValue = -1s ;
>>>> Npp_1km:valid_range = 0s, -36s ;
>>>> Npp_1km:calibrated_nt = 23 ;
>>>> Npp_1km:add_offset_err = 0. ;
>>>> Npp_1km:add_offset = 0. ;
>>>> Npp_1km:scale_factor_err = 0. ;
>>>> Npp_1km:scale_factor = 0.0001 ;
>>>>
>>>> " OBJECT = NORTHBOUNDINGCOORDINATE\n",
>>>> " NUM_VAL = 1\n",
>>>> " VALUE = 69.9999999937138\n",
>>>> " END_OBJECT = NORTHBOUNDINGCOORDINATE\n",
>>>> "\n",
>>>> " OBJECT = SOUTHBOUNDINGCOORDINATE\n",
>>>> " NUM_VAL = 1\n",
>>>> " VALUE = 59.9999999946118\n",
>>>> " END_OBJECT = SOUTHBOUNDINGCOORDINATE\n",
>>>> "\n",
>>>> " OBJECT = EASTBOUNDINGCOORDINATE\n",
>>>> " NUM_VAL = 1\n",
>>>> " VALUE = -119.983333303015\n",
>>>> " END_OBJECT = EASTBOUNDINGCOORDINATE\n",
>>>> "\n",
>>>> " OBJECT = WESTBOUNDINGCOORDINATE\n",
>>>> " NUM_VAL = 1\n",
>>>> " VALUE = -179.999999938971\n",
>>>> " END_OBJECT = WESTBOUNDINGCOORDINATE\n",
>>>> "\n",
>>>>
>>>> _______________________________________________
>>>> ncl-talk mailing list
>>>> List instructions, subscriber options, unsubscribe:
>>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>> _______________________________________________
>>> ncl-talk mailing list
>>> List instructions, subscriber options, unsubscribe:
>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
> _______________________________________________
> ncl-talk mailing list
> List instructions, subscriber options, unsubscribe:
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
_______________________________________________
ncl-talk mailing list
List instructions, subscriber options, unsubscribe:
http://mailman.ucar.edu/mailman/listinfo/ncl-talk
Received on Tue Aug 30 12:16:25 2011