Basic IDL Tools for extracting information from TES L3 HDF Product files.

Release August, 2007 for version F01 files.


These routines are written in Research System, Inc. Interactive Data Language (IDL).
IMPORTANT NOTE: These routines only work with IDL version 6.3 and higher
for reading format version F01 Level 3 files.
version F01 summary files.

CONTENTS:

1) Introduction and Overview
2) Summary of each routine and its usage
3) Contact Information


1) INTRODUCTION AND OVERVIEW

The routines covered by this README are:

read_l3_hdf.pro            
get_data_attributes.pro    (support routine--not called directly by the user)

The routines and this readme file are distributed in a Unix .tar file package
which may also be unbundled using extraction software such as WinZip.  The
tar file was written such that a directory named TES_L3ReadSoftwareV1 will be
created under the current directory where the tar file is placed, and the IDL
program files will be written into that directory.

The read_l3_hdf.pro routine takes the name of a TES L3 HDF product file 
(NOTE:  this routine does not work with Level 3 browse image files) and returns
all or some portion of the file.  The subroutine get_data_attributes.pro
is a support routine used by the read_l2 routines and should not be called 
directly.


For the above routines, a standard IDL documentation header
has been placed at the top of each file.  This document summarizes 
the naming and calling information for each routine.  For details of the 
the available keywords and the returned data, please see the header 
in each file.  For details of the TES L3 HDF product file specifications,
please see the Data Products Specifications (DPS) document,
http://eosweb.larc.nasa.gov/PRODOCS/tes/DPS/.

SIDE NOTE:
IDL has a nice GUI tool for browsing HDF files called h5_browser.
It will show you the structure of the HDF file and all of the
data, and allow you to export it to the IDL command line.  Using
this tool with a sample TES L2 HDF file will help one quickly become
acquainted with the contents of TES L2 HDf files.


2) SUMMARIES OF EACH ROUTINE AND ITS USAGE


----
read_l3_hdf.pro
----

This routine returns the complete of a TES L3 HDF file.

Calling syntax:

 	read_l3_hdf,file, $
                nadirgrid=nadirgrid, $
                nadirdaygrid=nadirdaygrid, $
                nadirnightgrid=nadirnightgrid, $
                limbgrid=limbgrid, $
                limbdaygrid=limbdaygrid, $
                limbnightgrid=limbnightgrid, $
                file_attributes = file_attributes, $
                hdfeos_data = hdfeos_data, $
                status = status,read_ph=read_ph, $
                show_options = show_options, $
                list_grids = list_grids, $
                actual_grids = actual_grids

        where file is the Level 3 input file name(string).  The keyword
        parameters are used to specify the data to be obtained from the
        file.  The nadir and limb grid keywords can be set to a variable
        which, on return, will contain a structure with retrieved data 
        from that grid, if the grid exists.  File attributes and HDF-EOS
        structural metadata are returned if those keywords have variables
        assigned to them.  The status keyword can be set
        to a variable which will receive a status code for the read.  The
        possible status values are defined in the file header.  The
        read_ph, show_options, and list_grids keywords will
        return information if set to a value of one or specified with a
	slash, e.g., list_grids=1 or /list_grids.  If read_ph is set and
	the file contains production history information, that information
	is returned.  If the list_grids keyword is set, the names
	of the grids contained in the file are printed.  The names of grids 
	can also be returned by setting the actual_grids keyword to a variable.
        If the show_options keyword is set, it will print the names of all
	possible grids.


3) CONTACT INFORMATION

Questions about using these routines may be directed to:

           NASA Langley Atmospheric Science Data Center
           User and Data Services Office
           NASA Langley Research Center
           Mail Stop 157D
           Hampton, Virginia 23681-2199
           U.S.A.

           E-mail:   support-asdc@earthdata.nasa.gov
           Phone:    (757)864-8656
           FAX:      (757)864-8807