[ncl-talk] cloudsat data

Dennis Shea shea at ucar.edu
Wed Dec 10 16:39:51 MST 2014


Please do not send direct emails to me. Only ncl-talk. The group is cc'd
here.

ncl-talk expects people to put in the time to learn the language.
ncl-talk can not do programing for you.
====

There are two excellent tutorials at:
http://www.ncl.ucar.edu/Document/Manuals/
Please look at the two DKRZ tutorials.

========
As noted on ncl-talk many times, the key to data processing is *KNOW YOUR
DATA*

Please read the description of the 'ncl_filedump' command line operator.
This provides an overview of a file's contents.

http://www.ncl.ucar.edu/Document/Tools/ncl_filedump.shtml

========

%> ncl_filedump 2010153190053_21792_CS_2B-
CLDCLASS_GRANULE_P_R04_E03.hdf

 Copyright (C) 1995-2014 - All Rights Reserved
 University Corporation for Atmospheric Research
 NCAR Command Language Version 6.2.0
 The use of this software is governed by a License Agreement.
 See http://www.ncl.ucar.edu/ for more details.

Variable: f
Type: file
filename:       2010153190053_21792_CS_2B-CLDCLASS_GRANULE_P_R04_E03
path:   2010153190053_21792_CS_2B-CLDCLASS_GRANULE_P_R04_E03.hdf
   file global attributes:
      HDFEOSVersion : HDFEOS_V2.5                   <=*=*=*=*=*=*=*=*=
      StructMetadata_0 : GROUP=SwathStructure  <=*=*=*=*=*=*=*=*=
        GROUP=SWATH_1
                SwathName="2B-CLDCLASS"
                GROUP=Dimension
                        OBJECT=Dimension_1
                                DimensionName="nray"
                                Size=37082
                        END_OBJECT=Dimension_1
                        OBJECT=Dimension_2
                                DimensionName="scalar"
                                Size=1
                        END_OBJECT=Dimension_2
                        OBJECT=Dimension_3
                                DimensionName="nbin"
                                Size=125
                        END_OBJECT=Dimension_3
                END_GROUP=Dimension

[SNIP ...]
++++++++++++++++++++

Comment: This is a HDF-EOS file with a SWATH structure.
Unfortunately HDFEOS is a separate format from classic HDF.
In practice, a 2nd read must be implemented. NCL does this by
appending a .he2 (or .hdfeos) suffix to the file name when reading the
file. NCL merges
the information from both reads. The hdf-eos part usually have latitude and
longitude.


%> ncl_filedump 2010153190053_21792_CS_2B-CLDCLASS_GRANULE_P_R04_E03.hdf.he2

Copyright (C) 1995-2014 - All Rights Reserved
 University Corporation for Atmospheric Research
 NCAR Command Language Version 6.2.0
 The use of this software is governed by a License Agreement.
 See http://www.ncl.ucar.edu/ for more details.

Variable: f
Type: file
filename:       2010153190053_21792_CS_2B-CLDCLASS_GRANULE_P_R04_E03.hdf
path:   2010153190053_21792_CS_2B-CLDCLASS_GRANULE_P_R04_E03.hdf
   file global attributes:

[SNIP ... you can ignore these here]

  dimensions:
      nray_2B_CLDCLASS = 37082
      scalar_2B_CLDCLASS = 1
      nbin_2B_CLDCLASS = 125
   variables:
      short cloud_scenario_2B_CLDCLASS ( nray_2B_CLDCLASS, nbin_2B_CLDCLASS
)
         hdfeos_name :  cloud_scenario
         valid_range :  ( 0, 32767 )
         units :        none
         long_name :    Cloud scenario
         offset :        0
         factor :        1
[SNIP]
      short Height_2B_CLDCLASS ( nray_2B_CLDCLASS, nbin_2B_CLDCLASS )
         hdfeos_name :  Height
         _FillValue :   -9999

      float Longitude_2B_CLDCLASS ( nray_2B_CLDCLASS )
         long_name :    longitude
         units :        degrees_east
         hdfeos_name :  Longitude

      float Latitude_2B_CLDCLASS ( nray_2B_CLDCLASS )
         long_name :    latitude
         units :        degrees_north
         hdfeos_name :  Latitude

     float Profile_time_2B_CLDCLASS ( nray_2B_CLDCLASS )
         hdfeos_name :  Profile_time


=========
After looking at your file, it is *NOT* a latitude-longitude grid.
It is a satellite swath (time, location, height_profile)


Good luck





On Wed, Dec 3, 2014 at 11:29 PM, Anusha sathyanadh <anushacalicut at gmail.com>
wrote:

> Dear Sir,
>
> I wish to know how to plot lat-lon contour maps like those shown here
> https://www.ncl.ucar.edu/Applications/cloudsat.shtml, over Indian region
> by using 2B-CLDCLASS data..Am attaching one of the data file along with ..
>
> On Wed, Dec 3, 2014 at 11:40 AM, Dennis Shea <shea at ucar.edu> wrote:
>
>> ncl-talk does not have any of these files readily available.
>>
>> wrt: 'how to plot lat-lon map using the data when the data is not on
>> regular grids and is not a function of lat and lon separately'
>> This is not clear ... ?lat and lon separately?
>>
>> The http://www.ncl.ucar.edu/Applications/Scripts/cloudsat_1.ncl
>> example file had the lat and lon as part of the file.
>>
>> NCL can plt 'anything' if the lat/lon data are available.
>> egL satellite swath data:  http://www.ncl.ucar.edu/Applications/HDF.shtml
>>
>> More cloudsat info is at:
>>
>>
>> http://www.cloudsat.cira.colostate.edu/dataICDlist.php?go=list&path=/2B-CLDCLASS
>>
>> Good luck
>>
>> On Tue, Dec 2, 2014 at 10:29 PM, Anusha sathyanadh <
>> anushacalicut at gmail.com> wrote:
>>
>>> Dear NCL users,
>>>
>>> I have a doubt concerning how to to use cloudsat 2B-CLDCLASS data for
>>> vertical and horizontal classification of clouds. the product gives
>>> cloud_scenario and  height with dimension of (nbin,nray). I have gone
>>> through the ncl talks regarding this and tried the instructions listed. I
>>> could plot the satellite path and height from the data. but I wish to know
>>> how to plot lat-lon map using the data when the data is not on regular
>>> grids and is not a function of lat and lon separately...
>>> cloud reflectivity lat lon map is plotted in this program
>>> https://www.ncl.ucar.edu/Applications/Scripts/cloudsat_1.ncl..is it
>>> possible for cloud scenario??
>>>
>>>
>>>
>>>
>>> waiting for your suggestions..
>>>
>>>
>>>
>>> --
>>>
>>>
>>>
>>>
>>> *ANUSHA SATHYANADHSenior Research FellowDeparment of Atmospheric and
>>> Space SciencesPune university*
>>>
>>> _______________________________________________
>>> ncl-talk mailing list
>>> List instructions, subscriber options, unsubscribe:
>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>
>>>
>>
>
>
> --
>
>
>
>
> *ANUSHA SATHYANADHSenior Research FellowDeparment of Atmospheric and Space
> SciencesPune university*
>
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