[daip] [Fwd: BB255CB and CD]

Fri May 8 16:26:00 EDT 2009

Hi Andreas,

You can also load the fits files that come from the correlator and then the 
concatenation will work in FITLD.

Amy

Eric Greisen wrote:
> Andreas Brunthaler wrote:
>> Hi Amy,
>>
>> it is pass 4 (the only one with only 16 channels). The files are:
>>
>> BB255CB/BB255CB_4_HPOL4IF8MHZ16CH_22.197GHZ00
>> BB255CD/BB255CD_4_HPOL4IF8MHZ16CH_22.197GHZ00
>>
>> Thanks,
>> Andreas
>>
>>
>> Amy Mioduszewski wrote:
>>> Hi Andreas,
>>>
>>> I am going to try to download your data and reproduce your problem. 
>>> Which pass were you doing?
>>>
>>> Thanks,
>>>
>>> Amy
>>>
>>> Andreas Brunthaler wrote:
>>>
>>>> Dear Eric,
>>>>
>>>> Eric Greisen wrote:
>>>>
>>>>>> Dear Analysts,
>>>>>>
>>>>>> I have downloaded the data from BB255CB and CD today from  the 
>>>>>> archive
>>>>>> (the 16 channel pass). When I try to load the two datasets with fitld
>>>>>> and doconcat 1 I get the following error:
>>>>>>
>>>>>> PC2004> FITLD1: Task FITLD  (release of 31DEC09) begins
>>>>>> PC2004> FITLD1: MISMATCH           6           2  AXIS COUNT
>>>>>> PC2004> FITLD1: ERROR      1 RETURNED FROM UVFHDR
>>>>>> PC2004> FITLD1: Purports to die of UNNATURAL causes
>>>>>> PC2004> FITLD1: pc20045      31DEC09 TST: Cpu=       0.0  
>>>>>> Real=       0
>>>>>>
>>>>>> The headers are almost identical:
>>>>>>
>>>>>> AIPS 1: Image=MULTI     (UV)         Filename=BB255C      .FXPOL 
>>>>>> .   1
>>>>>> AIPS 1: Telescope=VLBA               Receiver=
>>>>>> AIPS 1: Observer=BB255               User #=  255
>>>>>> AIPS 1: Observ. date=08-APR-2009     Map date=05-MAY-2009
>>>>>> AIPS 1: # visibilities   1046761     Sort order  TB
>>>>>> AIPS 1: Rand axes: UU-L-SIN  VV-L-SIN  WW-L-SIN  TIME1  BASELINE
>>>>>> AIPS 1:            SOURCE  FREQSEL  INTTIM  GATEID  CORR-ID
>>>>>> AIPS 1:
>>>>>> ----------------------------------------------------------------
>>>>>> AIPS 1: Type    Pixels   Coord value     at Pixel     Coord incr  
>>>>>> Rotat
>>>>>> AIPS 1: COMPLEX      3   1.0000000E+00       1.00  1.0000000E+00   
>>>>>> 0.00
>>>>>> AIPS 1: STOKES       2  -1.0000000E+00       1.00 -1.0000000E+00   
>>>>>> 0.00
>>>>>> AIPS 1: FREQ        16   2.2197040E+10       0.53  5.0000000E+05   
>>>>>> 0.00
>>>>>> AIPS 1: IF           4   1.0000000E+00       1.00  1.0000000E+00   
>>>>>> 0.00
>>>>>> AIPS 1: RA           1    00 00 00.000       1.00       0.000000   
>>>>>> 0.00
>>>>>> AIPS 1: DEC          1    00 00 00.000       1.00       0.000000   
>>>>>> 0.00
>>>>>> AIPS 1:
>>>>>> ----------------------------------------------------------------
>>>>>> AIPS 1: Coordinate equinox 2000.00
>>>>>>
>>>>>>
>>>>>> and
>>>>>>
>>>>>> AIPS 1: Image=MULTI     (UV)         Filename=BB255C      .FXPOL 
>>>>>> .   2
>>>>>> AIPS 1: Telescope=VLBA               Receiver=
>>>>>> AIPS 1: Observer=BB255               User #=  255
>>>>>> AIPS 1: Observ. date=09-APR-2009     Map date=05-MAY-2009
>>>>>> AIPS 1: # visibilities    970096     Sort order  TB
>>>>>> AIPS 1: Rand axes: UU-L-SIN  VV-L-SIN  WW-L-SIN  TIME1  BASELINE
>>>>>> AIPS 1:            SOURCE  FREQSEL  INTTIM  GATEID  CORR-ID
>>>>>> AIPS 1:
>>>>>> ----------------------------------------------------------------
>>>>>> AIPS 1: Type    Pixels   Coord value     at Pixel     Coord incr  
>>>>>> Rotat
>>>>>> AIPS 1: COMPLEX      3   1.0000000E+00       1.00  1.0000000E+00   
>>>>>> 0.00
>>>>>> AIPS 1: STOKES       2  -1.0000000E+00       1.00 -1.0000000E+00   
>>>>>> 0.00
>>>>>> AIPS 1: FREQ        16   2.2197040E+10       0.53  5.0000000E+05   
>>>>>> 0.00
>>>>>> AIPS 1: IF           4   1.0000000E+00       1.00  1.0000000E+00   
>>>>>> 0.00
>>>>>> AIPS 1: RA           1    00 00 00.000       1.00       0.000000   
>>>>>> 0.00
>>>>>> AIPS 1: DEC          1    00 00 00.000       1.00       0.000000   
>>>>>> 0.00
>>>>>> AIPS 1:
>>>>>> ----------------------------------------------------------------
>>>>>> AIPS 1: Coordinate equinox 2000.00
>>>>>>
>>>>>> Do you have any idea why I get this error?
>>>>>>
>>>>>> Cheers,
>>>>>> Andreas
>>>>>
>>>>> This is a bizarre looking error - the number of axes being 2 would 
>>>>> apply
>>>>> to some simple images perhaps although aips normally makes more axes
>>>>> than that.  There was a bug in FITLD that I fixed in 31DEC09 on 
>>>>> April 10
>>>>> which conceivably could be behind this problem although the testing 
>>>>> that
>>>>> I did showed other issues mostly not serious.  Try bringing your 
>>>>> version
>>>>> up to date and re-running FITLD.
>>>>
>>>> I tried it both with our MPIfR installation and on my laptop (after
>>>> bringing it up to date). Still the same problem. However, if I load 
>>>> both
>>>> files separately and use DBCON, it seems to work.
>>>>
>>>> Andreas
>>>>
>>>>
>>
>>
> I have looked at this issue and now understand it.  When the data being 
> read are from FITTP or FITAB, DOCONCAT cannot work.  Actually I do not 
> understand why we don't allow it for regular FITTP output - although it 
> would be a lot of work to disentangle issues of renumbering antennas, 
> sources, FQIDs, etc.  But for FITAB output - after FITAB was corrected 
> to be a proper rather than cheating implementation of FITS tables - 
> nothing is known about the structure of the UV data until the UV table 
> itself has had its header parsed.  Thus we cannot decide in advance 
> whether concatenation is allowed or not and we have to write the other 
> tables somewhere before we get to the uv data table.
> 
> I have changed the fortran to ignore DOCONCAT for files other than those 
> directly from the correlator and the help to make it clear that DOCONCAT 
> applies only the FITS-IDI files from the correlator.
> 
> DBCON may be run on the files after they are loaded - although they may 
> require MATCH first since DBCON will not renumber antennas (it does do 
> sources and FQIDs).
> 
> Eric Greisen
> 