[evlatests] Testing the 'subreflector rotation trick'

[Bryan Butler]

i believe that is an escaper that goes directly into the script, so 
whatever you are typing in goes in the script right there.  it will 
affect all subsequent scans unless you put in an escaper later to turn 
it off.

	-bryan


Rick Perley wrote:
>     Ken and I tested Barry's implementation of the 'subreflector 
> rotation trick'. 
> 
>     The following sequence of observations was set up, all at K-band:
> 
>     1) Regular observation of the source.
>     2) Determine referenced pointing offsets.
>     3) Observe source with offset pointing corrections applied.
>     4) Determine referenced pointing offsets, with corrections applied 
> (to check if they are really on).
>     5) Observe source with offsets applied.
>     6) Turn on the 'subreflector rotation trick' via an escaper command:
> //  \subarray.setRotate(1)
>        which followed the first source card that we wanted to try this 
> on.  According to my understanding, this applies the 'trick' to this, 
> and all subsequent cards (and not to any of the preceding cards). 
>     7) Observe source with offsets, and rotation, applied.
>     8) Determine referenced pointing offsets, with corrections 
> determined from #2 applied.
>     9) Observe source with offsets, and rotation, applied.
> 
>     Three difference sources were observed: 
> 
>     3C84, at elevation 82 degrees
>     0423-013, at elevation 54 degrees
>     0403-360, at elevation 20 degrees.
> 
>     Results:
> 
>     Cofirmation that the 'trick' is being correctly applied would be to 
> see a distinct rise in correlated amplitude (especially for the low 
> elevation source) between observations 5 and 7. 
>     In fact, for no antenna, and for no source, was *any* change in 
> amplitude seen between these scans.  Indeed, the only change in 
> amplitude seen was between the observations 1 and 3 -- before and after 
> the initial referenced pointing determination. 
>     Thus, the data are consistent with no application of the 
> subreflector rotation occurring. 
> 
>     Did I mis-type the escaper command?
>     Does that command apply itself to all scans, independent of the 
> location of the escaper?
> 
> 
>   
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