[daip] a problem with apcal

[Eric Greisen]

Thomas Krichbaum wrote:
> Hi Eric,
> 
> perhaps I have an idea. The data on which I am working now show a different 'sign'
> in the Y station coordinate compared to other experiments I have recently  analyzed. 
> 
> This are data from May 2009 of the Bonn MKIV Korrelator. VPLOT shows negative elevations.
> So APCAL perhaps does not work since it may flag the Tsys
> values probably becasue of the wrong elevation. Could that be ?
> 
> Do I need to fringe fit again (I used a CL table with PANG ), or is it sufficent to change
> the antenna coordinates using tbout/tbin ?
> 
> Btw: this data do not have subbarrays.
> 
> Thomas
> 
> here is the PRTAN output:
>  vlb051     PRTAN(31DEC11)     459               08-DEC-2011   17:34:02               Page    1
> File=GF014A3MM   .FITLD .   1     An.ver=   1     Vol= 2     User=  459
> Array= VLBI         Freq= 86210.990000 MHz     Ref.date= 07-MAY-2009
> 
> 
> Array reference position in meters (Earth centered)
> Array BX=         0.00000    BY=         0.00000    BZ=         0.00000
> Polar X =  -0.04586 Polar Y =   0.49771 arcsec
> Earth rotation rate =  360.9856449772 degrees / IAT day
> GST at UT=0 =  224.9675504910 degrees
> UT1-UTC=      0.2768950   Data time(UTC     )-UTC=      0.0000000 seconds
> XYZHAND = 'RIGHT   '    TFRAME = '?????   '
> Solutions not yet determined for a particular FREQID
> 
> Ant   1 = EFLSBERG BX=  4033947.4681 BY=  -486990.5090 BZ=  4900430.8095
> Mount=ALAZ  Axis offset=  0.0000 meters    IFA               IFB
> Feed polarization type =                    R                 L
> 
> Ant   2 = ONSALA60 BX=  3370606.0244 BY=  -711917.4814 BZ=  5349830.7378
> Mount=ALAZ  Axis offset=  0.0000 meters    IFA               IFB
> Feed polarization type =                    R                 L
> 
> Ant   3 = PICOVEL  BX=  5088967.9000 BY=   301681.6000 BZ=  3825015.8000
> Mount=ALAZ  Axis offset=  0.0000 meters    IFA               IFB
> Feed polarization type =                    R                 L
> 
> Ant   4 = PDBURE   BX=  4523987.1000 BY=  -468042.5000 BZ=  4460319.0000
> Mount=ALAZ  Axis offset=  0.0000 meters    IFA               IFB
> Feed polarization type =                    R                 L
> 
> Ant   5 = METSAHOV BX=        0.0000 BY=        0.0000 BZ=        0.0000
> Mount=ALAZ  Axis offset=  0.0000 meters    IFA               IFB
> Feed polarization type =                    R                 L
> 
> Ant   6 = VLBA_FD  BX= -1324009.1311 BY=  5332181.9699 BZ=  3231962.4738
> Mount=ALAZ  Axis offset=  2.1320 meters    IFA               IFB
> Feed polarization type =                    R                 L
> 
> Ant   7 = VLBA_NL  BX=  -130872.2576 BY=  4762317.1200 BZ=  4226851.0400
> Mount=ALAZ  Axis offset=  2.1290 meters    IFA               IFB
> Feed polarization type =                    R                 L
> 
> Ant   8 = VLBA_OV  BX= -2409150.1154 BY=  4478573.2303 BZ=  3838617.3978
> Mount=ALAZ  Axis offset=  2.1321 meters    IFA               IFB
> Feed polarization type =                    R                 L
> 
> Ant   9 = VLBA_PT  BX= -1640953.7151 BY=  5014816.0252 BZ=  3575411.8802
> Mount=ALAZ  Axis offset=  2.1385 meters    IFA               IFB
> Feed polarization type =                    R                 L
> 
> Ant  10 = VLBA_BR  BX= -2112064.9790 BY=  3705356.5179 BZ=  4726813.7976
> Mount=ALAZ  Axis offset=  2.1308 meters    IFA               IFB
> Feed polarization type =                    R                 L
> 
> Ant  11 = VLBA_KP  BX= -1995678.6300 BY=  5037317.7148 BZ=  3357328.1285
> Mount=ALAZ  Axis offset=  2.1325 meters    IFA               IFB
> 
> Ant  12 = VLBA_MK  BX= -5464074.9627 BY=  2495249.1140 BZ=  2148296.8426
> Mount=ALAZ  Axis offset=  2.1342 meters    IFA               IFB
> Feed polarization type =                    R                 L
> 
> Ant  13 = VLBA_LA  BX= -1449752.3630 BY=  4975298.5915 BZ=  3709123.9273
> Mount=ALAZ  Axis offset=  2.1325 meters    IFA               IFB
> Feed polarization type =                    R                 L

Yes - all Y coordinates are backwards - this is a LEFT hand system at 
present.  If you use PUTTH to set the KEYWORD 'XYZHAND' to say LEFT then 
AIPS will automagically fix your AN file.  It is unfortunate the the 
correlator has chosen to upgrade the table format without getting the 
parameters correct (if that is what has happened).  When  aips corrects 
an AN table it changes the KEYWORDs, the number of columns, and fixes 
the Y coordinate for recognized stations which these should be.

Eric Greisen