AIPS:  2005 Quarter 3

Key Developments

1.   Methods were developed in the last quarter of 2004 to allow for
binary distribution of AIPS.  In the first nine months of 2005, 43
sites downloaded the frozen 31DEC04 version and 221 sites downloaded
the development 31DEC05 version of AIPS using this capability.  So
far, a total of 219 sites have downloaded 31DEC04, 676 sites have
downloaded 31DEC05, and 801 sites have used the AIPS cvs code
management facility.  In all, 1216 different sites (different IP
addresses) appear in one or more of these lists.

2.   The binary version for Linux sites was changed to use the Intel
compiler.  The load modules are prepared in a form that optimizes
performance for older and current Pentium IV cpus but also allows
excellent performance on other computers such as AMDs.  For the older
Pentium IVs, the performance improvement is about 35%.

3.   When VLBI data are correlated, an estimate of the location of the
Earth's pole must be used.  Some weeks later, a better measurement of
the Earth's pole become available.  Due to an error, rather poor
estimates of the pole position were used over the past couple of
years, but even with the best estimates, better information becomes
available at a later time.  The AIPS task CLCOR now has the option to
use the later information to correct the estimates that were used
during correlation.  The data reading task FITLD was also modified to
put the pole position information in a more usable form for CLCOR.

4.   Work on spectral index imaging has begun.  A new task SPIXR was
written to fit spectral index and curvature to a spectral cube,  The
task that builds cubes was modified to allow frequencies that are not
regularly spaced to be made into a cube with the correct frequency
information saved in a table.  The image and UV data modeling tasks
were modified to allow more model components and spectral-index
variation in the components.

5.   Other new tasks include one to copy calibration tables between
polarizations and another to scale amplitudes in uv data.  A service
task to convert a public-catalog (multi-user) installation into the
now normal one user per catalog installation was written.

6.   A new model for the primary flux calibrator 3C48 at 21cm
wavelength was released.  The code that handles dynamic memory
allocation in AIPS was revised to work almost always even on computers
that use 64 bits for addressing.  The automatic flagging task was
corrected to flag data that fail to convert from baseline to antenna
based forms; it now appears to eliminate most of the bad data.  The
tasks that image single-dish data were modified to handle data from
the Green Bank Telescope.  Numerous other improvements and bug fixes
were also made during the quarter.



Goals for the Fourth Quarter 2005

1.   Continue user support and bug fixes, as the major portion of AIPS 
effort.

2.   Add to the task which computes the fluxes of the primary flux
calibration sources new (2004) flux values and interpolation in time
between the tabulated values.

3.   Provide support for pipeline data reduction, especially new
automatic editing algorithms.

4.   Begin investigations of new/improved imaging algorithms,
including those dealing with spectral index and multiple pointings.

5.   Install modern world coordinate handling software to enhance
and replace the original AIPS coordinate handling.