#------------------------------------------------------------------------------
#
#  NSSDC/CDF						CDFmerge online help.
#
#  Version 1.0, 25-Jul-06, Raytheon.
#
#  Modification history:
#
#   V1.0  25-Jul-06, M Liu 	Original version.
#   V1.1  12-Mar-07, M Liu 	Populated the help message.
#
#------------------------------------------------------------------------------

CDFmerge merges two or more CDFs into a single CDF.

Edit fields for...

  Source CDF1:    The first CDF to be merged.
  Source CDF2:    The second CDF to be merged.
  Source CDF3:    The third CDF to be merged.

                  Click on the "Select" button to select a desired CDF.  

                  One can specify up to 3 CDF files from the GUI.  If more 
                  than 3 files need to be merged, create a text file 
                  containing the name of input files (one CDF on each line) 
                  followed by the ouput CDF file name (last line).  Provide 
                  this text file name  in the "Input file name (optional):" 
                  box.
                      
  Output CDF:     The file name of the output file.

  Input file name (optional):      
                  The name of the input text file.  If more than 3 files 
                  need to be merged, create a text file containing the name 
                  of the input files (one CDF on each line) followed by 
                  the ouput CDF file name (last line).  Provide this text 
                  file name in this box.
                    
                      Example: 
                           cdf1.cdf
                           cdf2.cdf
                           .
                           .
                           cdfN.cdf
                           my_merged.cdf
                             
  Master CDF/file (optional):
                  Specifies to use the value of the global attributes
                  in the master CDF file (master_CDF) or text 
                  file (master_text) instead of getting the value of the 
                  global attributes.  Some attributes in the master_CDF or 
                  master_text are also used to construct the merged file name. 

                  The given master file name is checked first to see if it 
                  is a CDF file (master_CDF).  If it is not a CDF file, then 
                  it is treated as a mater text file (master_text).  

                  If a global attributed named "File_naming_convention" exists
                  in the master_CDF or master_text, its value and pattern 
                  are used to construct the leading portion of the output file 
                  name. Also, a time stamp and data version are added to the 
                  output file name. The Epoch or Range_epoch data from source
                  CDFs are checked to determine the time stamp.  
                  The Data_version attribute is used for calculating the data 
                  version number. 

                  If the File_naming_convention attribute does not exist, then
                  the Logical_file_id attribute is used to construct the 
                  output file name.  The timestamp portion of the file name 
                  is updated from the source CDFs's Epoch/Range_epoch data.  
                  If the Logical_file_id attribute doesn't exist, the program 
                  will search for the existence of the following attributes in
                  the order specified here to construct the output file name: 
                  Source_name, Descriptor, and Data_type. If any of these 
                  attributes is missing or its entry doesn't exist, an error 
                  is issued as the output file name can not be determined.

                  Syntax for <master_text>:
                     Global attribute name on a separate line followed by a
                     colon (:).  The value(s) of the global attribute are
                     specified on separate line(s), one global attribute entry
                     per line, immediately after the global attribute name.
                     The following example illustrates how to specify/override
                     the value of the Logical_file_id, Logical_source, and
                     Instrument_type global attributes:

                        Line 1)  Logical_file_id:
                        Line 2)     tha_l1_fgm_20060816_v01
                        Line 3)
                        Line 4)  Logical_file_source:
                        Line 5)     tha_l1_fgm
                        Line 6)
                        Line 7)  Instrument_type:
                        Line 8)     FGE
                        Line 9)     FGM


                  If this option is used, the "Merge Data Only" option is
                  automatically turned on.


  Prefixes for source CDFs (optional):
                  Specifies to use the user provided prefixes instead of the
                  default prefixes.  Prefixes should be separated by a 
                  comma (,) without sapces (e.g. p1,p2,p3), and the number of 
                  prefixes must match the number of input/soucrce CDFs. The
                  first prefix followed by a underscore (_) is added to the 
                  beginning of each variable and global attribute in the 
                  first input CDF, the second prefix is added to the variables 
                  and global attributes in the second CDF, and so on.
                  If this option is specified, prefixes, separated by a ",",
                  The maximum length of each prefix is 20 characters.


Check boxes for...

  About:          Display the library version that tool uses.

  No prefix:      Specifies not to add prefixes to the variables in the merged
                  file.  See "Prefixes for source CDFs (optional)" for more
                  detailed information on the prefixes.

                  If this option is specified, each variable name in the
                  source CDFs is unique (CDF doesn't allow duplicate variable
                  name).  If there is a duplication variable, the merge 
                  process will abort. This option can not be used with 
                  the "Prefixes for source CDFs (optional)" option.

  Merge Data Only:          
                  If this option is selected, the merged file will not have
                  a separate variable for each variable in the source CDFs. 
                  Variables with the same name from the source CDFs will be
                  combined into one, keeping the same name without prefix in 
                  the merged file. The merged file will have the meta-data, 
                  i.e., global and variable attributes, from the first source 
                  CDF.  Since variable data will be combined in the order 
                  specified in the source CDFs, it's important to arranage
                  the source files in a proper sequence (if they are 
                  sequence-sensitive).  

  CDAWeb:         Specifies to create a merged file that is ISTP/CDAweb CDF
                  compliant.  The ISTP/CDAweb guideline is available at
                  http://spdf.gsfc.nasa.gov/istp_guide/istp_guide.html.
                  The 'epoch' variable is a mandatory variable in the
                  ISTP/CDAweb guideline.  Thus, the duplication of this
                  variable is allowed in the input CDFs.  The duplication of
                  the variable named "RANGE_EPOCH" (in any upper/lower case
                  combination) is also allowed.
 
  Augment_Label:  Specifies to create a variable attribute named AUGMENT_LABL 
                  and set its value to "TRUE" for all variables.


Buttons for...

  Enter              Causes CDFmerge to merge the requested CDFs. 

  Help               Causes this online help to be displayed.

  Quit               Exits CDFmerge.

