CDAW-HOWTO
----------

A quick introduction to using the cdaw-attr and pds-to-cdf programs to
generate CDAWeb-compatible CDF files from tabular PDS data files.

PREREQUISITES
-------------

In addition to the files supplied here, you'll need a recent Java
run-time to support the cdaw-attr Swing GUI, a copy of the clojure.jar
file either copied or linked into the pds-to-cdf directory, and a
complete installation of the CDF software to get the skeletoncdf
program.

PROCESSING FLOW
---------------

We'll assume that you have a series of related time-ordered PDS
data sets that you'd like to convert into CDF files suitable for
incorporation into the CDAWeb web site.  There are two main steps
involved in this process.  

First, the cdaw-attr program is used to specify a set of attributes
that describe the overall data collection.  This program writes out
"t.skt", a CDF skeleton file, and runs the skeletoncdf program
(furnished by the CDF software installation) to translate this into
the "t.cdf" file required for the next step.

Next, the pds-to-cdf program is used to translate one or more PDS
data sets into CDF files.  For plain CDF file, this is a simple matter
of running the pds-to-cdf program with the ".LBL" PDS label files to
be translated as arguments to the program.  While this same approach
is taken to generate CDAW-compatible CDF files, the additional
requirements of the CDAWeb site necessitate that a number of
additional options be supplied to the pds-to-cdf program.

The --cdaweb option triggers a few CDAWeb-specific processing options,
such as using a CDAWeb-compliant file name for the generated CDF file.
The --template option is required to supply the previously generated
"t.cdf" file containing CDAWeb-specific global CDF attributes.  Since
the CDAWeb site is geared toward temporal data sets the --epoch option
must be used to select the column and conversion process used to
calculate the observation time of each row of data.

When the attributes taken from the template .CDF file pertain to a
group of several PDS data files, these files can all be processed in a
single pds-to-cdf program run.

Finally, after generating a collection of CDF files, you'll want to
get them staged on the CDAWeb site.  I've always done this by copying
the .CDF files to my home directory on mambo and asking Howard Leckner
to perform a quick sanity check on the files and to stage them for
ingest into the CDAWeb system if all looks well.

FURTHER READING
---------------

The general operation of the  pds-to-cdf program is described in the
pds-to-cdf.1 man page.  Details of the CDAWeb-specific CDF file
requirements are described in the pds-to-cdaw.7 man page.