[daip] Error in AIPS task FILLM for polarimetry data

[Eric Greisen]

Amanda Kepley wrote:
>   Hi,
> 
> I recently received an email about the errors in the AIPS FILLM task for 
> polarimetry data. Although it looks like I'm not affected by the MODCOMP 
> turn off problem since my data were all taken prior to June 27, 2007, I 
> am not quite sure if I'm affected by second problem mentioned in the 
> email:  "The problem also affects data obtained in the Modcomp-era that 
> are loaded as correlation coefficients by FILLM, where FILLM has had to 
> "undo" the on-line nominal sensitivity scaling."  It seems like this is 
> mostly a problem with solar data, but I thought I'd double-check to make 
> sure. I usually load the data with doweight=10 and douvcomp false. Below 
> is an example of a typical FILLM I use for my data. My correlators setup 
> is 2 IFs of 50 MHz each. 

> ----------------------------------------------------------------------------------------------------
> 
>

> AIPS 1: CPARM         0           0        User options.
> AIPS 1:               0           0        1 => Avg. time (seconds)
> AIPS 1:               0           0        2 => bitmap    (see help)
> AIPS 1:               0           0.1           = 16 for planets & Sun
> AIPS 1:               0           0        3 => Max. OK IF status
> AIPS 1:                                         <=3 => 3
> AIPS 1:                                    4 => Control dropping of
> AIPS 1:                                         shadowed data
> AIPS 1:                                         < 0 => no shadow check
> AIPS 1:                                         0 => 25 m limit
> AIPS 1:                                         > 0 => Shadow limit is
> AIPS 1:                                               CPARM(4) in meters
> AIPS 1:                                    5 = channel code (see HELP)
> AIPS 1:                                    6 => Subarray number-see HELP
> AIPS 1:                                    7 => FQ entry tolerance (kHz)
> AIPS 1:                                         (see HELP)
> AIPS 1:                                    8 => CL table time incr. min
> AIPS 1:                                    9 => TY table time incr. min
> AIPS 1:                                    10=> Calibrator avg. time

the option to turn data into correlation coefficients is usually used 
only by people commissioning the telescope and wanting to study its 
behavior (or more misbehavior).  Setting CPARM(2)=2048 will achieve this 
and leave you with the need to apply the TY table later.  You have not 
invoked this option and so are not affected by the error except for the 
negligible affect on data weights.

Eric Greisen
Eric Greisen