[daip] TECOR

[Chris Flatters]

Jim Ulvestad <julvesta at aoc.nrao.edu> writes:

> I was using TECOR last week, and found it quite awkward to have to
> hack two files together for a VLBA run that went across midnight.
> There are no instructions for how to do so; I figured it out 
> eventually and managed to make it work, but at the expense of
> deleting the header for the second day's file (among other things),
> which means the first day's biases were used for the second day's
> file.

The bias information in the IONEX file records some information about
the model that was used to generate the maps. It is not used to
interpret the map data and we don't lose anything by deleting them.

> It seems that it would be easier just to tell users to run TECOR
> twice, once for each day's data, and fill the CL table appropriately.
> However, TECOR fails if it doesn't cover the entire time range of
> the CL table.
> 
> Is this easily fixable in AIPS, or do we need to supply the users
> with a recipe for concatenating files?

I think that it makes more sense to merge two or more IONEX data sets
outside AIPS to make a valid IONEX data set the covers the whole experiment
than to deal with multiple input files in AIPS. The effort involved in
writing a program to do this (including some checks that the input files
are compatible) should be relatively small, although I have not done a
serious cost estimate yet.

At the moment this is queued behind FXPOL and reviewing Ketan's VLBI
scripts but I'm hoping to be able to make a start on it by the end of May.

	Chris