Re: About plotting MODIS-Level-2 data

As noted by Andrea, there are numerous HDF [HDF-EOS] examples.

The first rule of data processing is *examine the data file*.

You can see the file's contents via

%> ncl_filedump MOD07_L2.A2010274.1740.005.2010275063051.hdf | less

Look at the variables, the type of variable (byte, short, float) and
read the ancillary information. Decide what you want/need.

Look at the dimensions of the variables; do the data need to be
unpacked? Do bits need to be extracted? NCL can do it all but
you must decide how to proceed.

Typically these MOD07_L2 are

       HDFEOSVersion : HDFEOS_V2.9
       StructMetadata_0 : GROUP=SwathStructure
         GROUP=SWATH_1

You will get the latitudes and longitudes of the the swath; if there are
multiple levels associated with a variable, there will be 3 dimensions
[generically: (level,latitude,longitude) ]

The hdf4eos_1.ncl thru hdf4eos_5.ncl examples at url below
are a good start for you.

Good luck

On 11/26/10 3:50 AM, Andrea Hahmann wrote:
> Dear Jayakrishnan
>
> There are quite a few examples of reading and plotting EOS data in
> http://ncl.ucar.edu/Applications/HDF.shtml
>
> Good luck!
> Andrea
> --
>
> *Andrea N. Hahmann
> *Senior Scientist
> Wind Energy Division
> Risø DTU
>
> *Technical University of Denmark
> *Risø National Laboratory for Sustainable Energy
> Frederikborgvej 399, P.O. Box 49
> 4000 Roskilde, Denmark
>
> Direct +45 4677 5471
> Mobil: +45 2133 0550
> ahah@risoe.dtu.dk
> www.risoe.dtu.dk
>
>
>
> ------------------------------------------------------------------------
> *From: *jayakrishnan pr <jkprdas@gmail.com>
> *Date: *Fri, 26 Nov 2010 04:33:02 -0500
> *To: *<ncl-talk@ucar.edu>
> *Subject: *[ncl-talk] About plotting MODIS-Level-2 data
>
> Can anyone help me by giving a programme which will plot the MODIS
> Level-2 atmospheric profile product. An example of the file name is
> given below.
>
> MOD07_L2.A2010274.1740.005.2010275063051.hdf
>
> The link from which it can be downloaded is
>
>
> http://ladsweb.nascom.nasa.gov/data/search.html
>
>
>
> --
> Jayakrishnan.P.R.
> CSIR-Research Fellow
> Department of Atmospheric Sciences,
> Cochin University of Science and Technology (CUSAT)
> Cochin-682016, mob:09895417565
>
> ------------------------------------------------------------------------
> _______________________________________________
> 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 Fri Nov 26 07:32:45 2010