[daip] Re: POSSM with BPARM normalisation (fwd)

[R. Niruj Mohan]

Hello,

Thanks for the email. The signal does drop at the
edges, as you say. However, the way the signal behaves
at the two edges is a bit funny, or atleast I cant
understand what it does at channel 1 and channel 15.

I have Q band data, with 15 channels, with no online
hanning smoothing. My BPcalibrator is 0316+413 with
one scan of 10min duration. I run a BPASS on it
(DOCALIB=2, GAINUSE=1, BPASSPRM=0, ICHANSEL=1,3,3,0
but choice of ICHANSEL doesnt affect results). I have
two BPASSes, one with SMOOTH=0 and another with
SMOOTH=1,0.

Then I run POSSM on the BPcalibrator *itself*, with
DOCALIB=2, GAINUSE=1, APARM=1,0, DOBAND=2,
BPARM=1,3,3,0, SOLINT=0, NPLOT=0 and for each BP
table, I have SMOOTH=0 and SMOOTH=1,0

I agree that the SMOOTH values for BPASS and POSSM
have to be the same else it doesnt make sense but I
wanted to see what the smoothing has done at the edge
channels. 

The 4 plots are attached as a tar file with suitable
names. As you can see, the flaring or not, of channels
1 and 15 without smoothing are toggled with smoothing.
The scales after smoothing are much smaller, for sure,
but is this (toggling) behaviour consistent with what
is expected at the edges ? 

Thanks!
Niruj

 --- Eric Greisen <egreisen at nrao.edu> a écrit : 

> Usually the edge channels have both small signal and
> rather varying
> phase so this may actually make the signal drop more
> 
> Eric Greisen
>  


	

	
		
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