The cationex Utility
The cationex utility is a stand-alone utility for combining data from
multiple IONEX data files into a single IONEX data file. It is intended
for combining data files from the CDDIS archive so that they may be used
as input to TECOR for experiments that cross midnight.
Building cationex
In order to build cationex, you will need a fairly recent version of GCC:
I recommend Version 2.95.2 or later. It should also be possible to use
any C++ compiler that is compliant with the ISO C++ standard but some minor
tweaking of the source may be required.
The first step is to unpack the archive file cationex.tar.
tar xvf cationex.tar
This will create a new directory that contains the source code for cationex
and some test data.
Change to the cationex directory and check the contents of
Makefile. If you are using a standard installation of GCC and
the g++ command is in your path then you should not need to make any modifications
but there is always a possibility that you will need to make some adjustments
to Section 1. After making any changes that might be necessary, issue the
make command. This will build cationex.
After building cationex, you should install it in a suitable
directory in most users' search path. I recommend placing it in $SYSLOCAL.
If you have system manager privileges, you might prefer /usr/local/bin.
Running cationex
In its basic mode, cationex takes a list of files and writes a
new IONEX file to the standard output. The new IONEX file contains all
of the TEC maps from the input files but discards any RMS or HEIGHT maps
that might be present. Most optional header information will also be discarded.
You may save the output by redirecting it to a file or by specifying
an output file using the -output flag as in this example.
cationex jplg0550.00i jplg0560.00i jplg0570.00i -output COMBINED.DATA
You will probably want to use an upper-case name for the output file so
that AIPS can read it.
You may print a usage summary by typing
cationex -help
Notes For Linux
The cationex utility uses Unix facilities for handling dates. Unfortunately,
Linux does not support the altzone interface that gives the offset
of the alternate local timezone (usually daylight savings time) from UTC.
On Linux systems cationex assumes that the alternate timezone
differs from the primary timezone by exactly 1 hour. This means that it
is possible that cationex will misbehave if unusual time zone
settings are used. Such problems should be rare.