On Tue, 8 Apr 2008, Paul Dyer wrote:

> Hi Vincent;
> We have the discs to correlate bf092aa. I see that you need to send
> positions/parameters. Please email these asap.
>
>
> Paul Dyer - NRAO Data Analyst

I attach a note to the correlator operators below.

On a related topic, does NRAO release data on DVDs yet?  I'm trying to 
move away from data on tape.  However, if tapes are the only option for 
data transfer, I will need data on DDS-3 DATs.  I don't think anyone has 
a DDS-4 drive here at Haystack.
 							Vincent

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Since experiment BF092 requires a complicated correlation setup, I am
sending this message to aid the correlator operators.  The two
complexities are 1) requirement of multiple correlation passes, and 2)
use of correlation positions not given in the SCHED keyin file or in
the standard source catalogues.

BF092 was set up to observe 4 narrow-bandwidth channels and
12 wide-bandwidth channels as follows:

ch #   1    2   3  4    5   6   7  8  9  10 11 12 13 14 15 16
BW    0.25 0.25 2  2  0.25 0.25 2  2  2  2  2  2  2  2  2  2

Correlation will require three passes, as follows:
   1) the 4-narrow band BBCs only, with 256 spectral channels per BBC
   2-3) all 16 BBCs using a typical "continuum" setup (16 spectral
   points per BBC), which will probably require two correlator passes

Scans fall into three different categories: calibrators, targets, and
"NEAR" scans.  The NEAR* scans represent scans during which the
telescope was pointed halfway between a maser target and a calibrator,
such that both are within the primary beam of a VLBA dish.  A complete
list of sources from BF092A-C follows:

   Calibrator sources
   ------------------
   J0613+1306           Coordinates from these
   3C84                   sources should be taken
   0609-0615              from the standard catalogues
   DA193                  if available, or from the
   J0606-0724             keyin files if not.  These
   1811-205               calibrator sources should be
   J1912+0518             correlated in BOTH the
   J1922+0841             narrow-BW and wide-BW
   3C345                  correlation passes.
   1921-293
   2312+6108
   J2254+6209
   2007+777
   3C454.3

   Target sources
   --------------
   MONR2                Coordinates for these sources are always
   G9.622                 given in the keyin files.  These target
   G43.796                sources should be correlated in the
   NGC7538                narrow-BW correlation pass only.

   "NEAR" sources
   --------------
   NEARS269             These sources require different coordinates
   NEARG40                for narrow-BW and wide-BW correlation,
   NEARCEPA               NEITHER OF WHICH is in the keyin file!


The NEAR* sources should be correlated in both the narrow-BW and the
wide-BW correlation passes, but the correlation centers are different!
Coordinates appear below (all J2000):

   Source        Narrow-BW pass           Wide-BW passes
                 RA          Dec          RA          Dec
   ------    -----------------------  -----------------------
   NEARS269  06:14:37.07  13:49:36.3  06:14:41.282    14:04:19.82
   NEARG40   19:06:01.61  06:46:35.8  19:05:21.211    06:52:10.78
   NEARCEPA  22:56:17.87  62:01:48.6  22:54:25.293029 62:09:38.72468

If you have any questions about the requested setups, please do not
hesitate to contact me at vfish@haystack.mit.edu .  Thanks a lot!
 							Vincent