[esa-t474] Typos corrected

[Yury Kolomensky]

	Hi Chris,

I can understand why a single-frequency fit would be susceptible to  
the beating between two modes, but why would DDC be ? It is linear by  
design (we toyed with 2-stage filtering, which would make the  
algorithm non-linear, but it does not improve resolution much, so  
this was abandoned). In DDC, the second polarization would show up as  
a shift in I/Q plane. But that shift would still be proportional to  
the offset in another direction, which can be taken out by regression  
(e.g. SVD). This seems to work more reliably than a two-component fit  
(which was attempted by Mark in NanoBPM analysis, IIRC, w/o much  
success).

Yury

On Dec 3, 2007, at 1:01 AM, Adolphsen, Chris wrote:

>
> Has anyone compiled a list of the size of the out-of-phase  
> components of the bpm signals - it might explain the 'low signal'  
> phenomena that is referred to in the paper (i.e., I believe one is  
> more sensitive to phase errors when the out-of-phase signals  
> dominates).
>
> BTW - Johnny is currently analyzing the bpm 3-5 signals and is  
> seeing that each signal (x and y) contains a mixture of the two  
> polarizations which differ in frequency at the MHz level (although  
> one dominates) - this can cause a pronounced beating effect when  
> the normally dominate mode is small, and will likely worsen the  
> resolution unless the signals are analyzed properly (e.g. doing a  
> two mode fit instead applying the DDC algorithm, which assumes one  
> mode).
>
>
> -----Original Message-----
> From: Mark Slater [mailto:slater at hep.phy.cam.ac.uk]
> Sent: Friday, November 30, 2007 9:49 AM
> To: esa-t474 at hep.ucl.ac.uk
> Subject: [esa-t474] Typos corrected
>
> Dear All,
>
> I have put in all the corrections I recieved except a few:
>
> 1)  I haven't added a measured vs. predicted plot for the resolution
> 2)  I haven't updated the energy vs. residual plot at the end of  
> the paper
> 3)  I still need to try to sort out bibtex for the references
> 4)  I have also yet to get a SLAC pub number or EuroTev number.
>
> I'll get these sorted over the weeked (as much as possible). but  
> I've uploaded everything else and so if I get the all clear on  
> Monday at the phone meeting, I'll submit on Tuesday.
>
> Many Thanks,
>
> Mark
>
> _______________________________________________
> esa-t474 mailing list
> esa-t474 at hep.ucl.ac.uk
> https://mail.hep.ucl.ac.uk/mailman/listinfo/esa-t474
>
> _______________________________________________
> esa-t474 mailing list
> esa-t474 at hep.ucl.ac.uk
> https://mail.hep.ucl.ac.uk/mailman/listinfo/esa-t474