[evlatests] Initialization problems

[Gregory Taylor]

Hi Walter,

    Here is an example of a labeling problem, LISTR output from
a fast-switching observation of the SGR0501+4516 field at 22 GHz.
Observation code is AG804 observed Wednesday morning (8/27)
from 9 to 12 IAT roughly. Only data from 10:12 to 10:22 was
affected, several other blocks were unaffected in exactly the
same observing mode.   Data itself can be found on
pegasus.aoc.nrao.edu, user 1547.  Let me know if you
have any questions.

Ciao,
                                              - Greg

Source=05011+45165     : 0000, Stokes=RR  , IF=  1, Chans=   1-   1
Flux =   .0000 Jy, Calcode =     , Freq = 22.485100000 GHz
Phase, 1000 = 1000.00 degrees, averging type = Vector

Baselines      1-22  2-22  4-22  5-22  6-22  7-22  8-22  9-22 10-22
  4/10:17:35     -4   -52   -21     2    13    63   -17   -36   -19
  4/10:17:55    -38   151   120    51   -68  -169  -134   -90   -98
  4/10:17:58    153  -109   179   134   -19  -114    84   -13   -70
  4/10:18:02     26   -62  -162    24    73    32    31   109   -58

Source=05026+41393     : 0000, Stokes=RR  , IF=  1, Chans=   1-   1
Flux =   .2136 Jy, Calcode = B   , Freq = 22.485100000 GHz
Phase, 1000 = 1000.00 degrees, averging type = Vector

Baselines      1-22  2-22  4-22  5-22  6-22  7-22  8-22  9-22 10-22
  4/10:18:05    -82    32  -173    82    90     3   142    56     7
  4/10:18:25     27     2     0    11   -59   -52     9    14    -5
  4/10:18:28      7   -79    13    19   -10     2   -27    29    28
  4/10:18:32      6   -22   -12   -84    16   -66     6    -7    16

Source=05011+45165     : 0000, Stokes=RR  , IF=  1, Chans=   1-   1
Flux =   .0000 Jy, Calcode =     , Freq = 22.485100000 GHz
Phase, 1000 = 1000.00 degrees, averging type = Vector

Baselines      1-22  2-22  4-22  5-22  6-22  7-22  8-22  9-22 10-22
  4/10:18:35    -82   -16   -45   -27    52    -1    15     5   -60
  4/10:18:55    114   -55   -86   166    74   158  -169    41  -102
  4/10:18:58     82   118   111   122    60  -160    98   155  -132
  4/10:19:02   -164   121  -103   -16   147   127    -3  -163   -77

Source=05026+41393     : 0000, Stokes=RR  , IF=  1, Chans=   1-   1
Flux =   .2136 Jy, Calcode = B   , Freq = 22.485100000 GHz
Phase, 1000 = 1000.00 degrees, averging type = Vector

Baselines      1-22  2-22  4-22  5-22  6-22  7-22  8-22  9-22 10-22
  4/10:19:05   -117   144   127  -128  -153   -21    28   -76  -158
  4/10:19:25     19   -17    31  -107     4    32    27     2    -1
  4/10:19:28     19    29   -20    37   -52    19   -47   -26   -35
  4/10:19:32    -16    34    -9   -85    17   -31    57    23   -52

Above you can see some scans on SGR 0501+4516.  Note that there is
one measurement, then a gap of 20 seconds (presumably while
the source change occurs), then three more measurements.  Then
we go to the calibrator, but look there is a 3 second record
with NO GAP as we would expect during a move.   If you stare at
the data you can also convince yourself that the lone 3 second
record has a phase near zero on SGR 0501 (because it came from
the calibrator), and the lone record on the calibrator has a more
random phase (because it came from SGR 0501).


On Aug 29, 2008, at 1:05 PM, Walter Brisken wrote:

>
> The first integration labeling issue is puzzling to me.  I've gone  
> over
> the idcaf code related to this again and it seems reasonable.  If an
> integration time ends in a new scan, it should be labeled as the new  
> scan,
> but flagged for the first integration.  Can someone point me to a  
> dataset
> where there is a supposed first integration labeling problem?  do we  
> know
> if it is the beginning or the end of the target source scan that has  
> the
> leakage from the calibrator?  The beginning is the only way I can  
> see that
> making any sense.
>
> Rick -- for this new problem, can you tell me the experiment name  
> and the
> time (UT prefered) that you saw incorrect frequencies so I can look  
> at the
> IDCAF logs to see what it thought was going on?
>
> Thanks,
>
> Walter
>
> On Fri, 29 Aug 2008, Ken Sowinski wrote:
>
>> On Fri, 29 Aug 2008, Rick Perley wrote:
>>
>>>  All of these tests involve short observations of multiple sources  
>>> at
>>> multiple frequencies and bands.  For all these tests -- with a  
>>> single
>>> exception-- the first observation is at P-band, in continuum, with
>>> requested frequencies of 327.5 and 307.5 MHz, and a bandwidth of  
>>> 3.125MHz.
>>
>> It looks like this has the same cause as the problem that idcaf
>> with the first scan if the correlator setup changes from the first
>> to second scan of a file.  Have we ever determined whether idcaf is
>> confused about what it is told or the executor is misinforming it?
>>
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