Re: Open MYD09GQ.A2006060.h25v06.005.2008075213332.hdf using a NCL script

From: Wei Huang <huangwei_at_nyahnyahspammersnyahnyah>
Date: Tue Dec 11 2012 - 11:12:37 MST

Filippo,

Could you please do:

ncl_filedump your-filename

and send the output to us?

Thanks,

Wei

huangwei@ucar.edu
VETS/CISL
National Center for Atmospheric Research
P.O. Box 3000 (1850 Table Mesa Dr.)
Boulder, CO 80307-3000 USA
(303) 497-8924

On Dec 11, 2012, at 9:05 AM, Filippo Locci wrote:

> Hi,
> using examples from http://www.hdfeos.org/zoo/index_openLPDAAC_Examples.php
> and modifing a script to open a MYD09GQ file but an error occurs:
> fatal:["Execute.c":5773]:variable (YDim) is not in file (eos_file)
>
> My script:
>
> ;This example code illustrates how to access and visualize LP_DAAC_MYD Grid file in NCL.
> ;If you have any questions, suggestions, comments on this example, please use the HDF-EOS Forum (http://hdfeos.org/forums).
> ;If you would like to see an example of any other NASA HDF/HDF-EOS data product that is not listed in the HDF-EOS Comprehensive Examples page (http://hdfeos.org/zoo),
> ;feel free to contact us at eoshelp_at_hdfgroup.org or post it at the HDF-EOS Forum (http://hdfeos.org/forums).
>
> load "$NCARG_ROOT/lib/ncarg/nclex/gsun/gsn_code.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
>
> ; This is an example of a 2-D grid file data field.
> ; It is assumed users know how to obtain information such as _FillValue from HDFView.
> ; For information about HDFView, visit http://www.hdfgroup.org/hdf-java-html/hdfview/.
>
> begin
>
> eos_file=addfile("MYD09GQ.A2006060.h25v06.005.2008075213332.hdf", "r") ; Read file.
> ; he2_file = addfile("MYD09A1.A2007273.h03v07.005.2007285103507.hdf.he2", "r") ; Read file for the second time to efficiently obtain lat and lon.
>
> ; List available fields and attributes.
> print(eos_file)
>
> ; read data field
> data_raw = eos_file->sur_refl_b01_1
>
> ; print(data_raw)
>
> ; Apply scale factor according to the field attribute
> ; correct_data_value = (raw_data_value - offset) * scale_factor
> data = (data_raw - data_raw@add_offset) * data_raw@scale_factor
>
> data@_FillValue = (data_raw@_FillValue - data_raw@add_offset) * data_raw@scale_factor
>
> data@long_name = data_raw@long_name
> data@units = data_raw@units
>
> ; Associate longitude and latitude
> ; data@lat2d=he2_file->GridLat_MOD_Grid_500m_Surface_Reflectance
> ; data@lon2d=he2_file->GridLon_MOD_Grid_500m_Surface_Reflectance
>
>
> lat=eos_file->YDim ; associate longitude and latitude
> lon=eos_file->XDim ;
> lat@_FillValue=-999.0
> lon@_FillValue=-999.0
>
>
> data@lat2d=lat
> data@lon2d=lon
>
>
> xwks=gsn_open_wks("pdf","MYD09GQ.A2006060.h25v06.005.2008075213332.hdf_sur_refl.ncl") ; open workstation
>
> res=True ; plot mods desired
> res@cnFillOn=True ; enable contour fill
> res@gsnMaximize=True; make plot large
> res@gsnPaperOrientation = "portrait" ; force portrait orientation
> res@cnLinesOn=False ; turn off contour lines
> res@cnLineLabelsOn = False; turn off contour line labels
> res@gsnSpreadColors = True ; use the entire color spectrum
> res@cnFillMode = "RasterFill" ; faster
> res@lbOrientation ="vertical" ;vertical labels
> res@cnMissingValFillPattern = 0 ; missing value pattern is set to "SolidFill"
> res@cnMissingValFillColor = 0; white color for missing values
>
> ; the following 5 sentences are used to create a zoomed image
> res@mpLimitMode = "LatLon"
> res@mpMinLatF = min(data@lat2d) ; Set limits of map, based on the min/max of the dataset latitude/longitude
> res@mpMaxLatF = max(data@lat2d) ;
> res@mpMinLonF = min(data@lon2d) ;
> res@mpMaxLonF = max(data@lon2d) ;
>
> gsn_define_colormap(xwks,"BlAqGrYeOrReVi200") ; choose colormap
> res@tiMainString = "MYD09GQ.A2006060.h25v06.005.2008075213332.hdf" ; create title
> res@gsnLeftString = "Field name: " + data@long_name
> res@gsnRightString = "Units: " + data@units
>
> plot=gsn_csm_contour_map_ce(xwks,data,res) ; create plot
>
> ; cleaning up used resources
> delete(plot)
> delete(res)
> delete(xwks)
> delete(data)
> delete(data_raw)
> delete(eos_file)
> ; delete(he2_file)
>
> end
>
> I haven't a file where I could read the geolocation. It's possible to read this file via HDF viewer but
> I'm not able to open this file via an NCL script.
> Please, give me a suggestion.
> Thank you
> F
> --
> Filippo Locci
> PhD Student
> International PhD in
> Environmental Science and Engineering
> University of Cagliari
> Tel. +390706757701
> Mob. +393471372292
>
> _______________________________________________
> 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 Wed Dec 12 03:13:00 2012

This archive was generated by hypermail 2.1.8 : Wed Dec 12 2012 - 19:07:01 MST