[daip] aips_gripe

[vfish at aoc.nrao.edu]

{10-OCT-2005 08:44:55}
{arielle      UN-REGISTERED!!!!!!!}
{   86  31DEC05  LINX}
{Vincent L. Fish}
{NRAO Socorro}
{(505)835-7098}
{Scenario: I recently obtained spectral-line VLBA data that required
   two correlator passes to correlate all the BBCs.  Correlator jobs
   1 through n contained 2 IFs, and jobs n+1 through 2n contained the
   other 2 IFs.  Erroneously or not, I loaded them into a single uv
   file with FITLD.  Then I ran VLBAFIX to sort the data and separate
   them by IF.
  
 Problem: VLBAFIX/MSORT cannot deal elegantly with this simple case.
   When MSORT started, it read
   MSORT1 15:45:09     410667 unsorted starting at         2 avg sep   102614
   I finally killed MSORT 31 hours later, when it had only progressed
   as far as the following
   MSORT1 22:54:15     321190 unsorted starting at     41543 avg sep    82876
   I'M SURE IT WOULD STILL BE GOING NOW, TWO DAYS LATER, IF I HADN't
   stopped it.  I'm currently reloading the data from scratch into two
   separated uv files.
  
 Suggested fix: VLBAFIX should be able to detect this very simple case and
   work around it.  If that's not easy to do, then perhaps MSORT should
   be modified to be able to quickly shuffle together the two time-ordered
   halves of a large uv file.
  }
{VLBAFIX/MSORT not intelligent on multiple corr passes in same uv file}
{vfish at nrao.edu}
{ }