Hi Colm, You are right.
PFB is a great way to reduce frequency smearing but the down-side is time smearing. A brief event will be convolved with at least one of your PFB 8-tap filters that end up feeding several FFT computations in a row. So, you get time smearing for that short event... Regards, Cedric Le 28/08/2020 à 11:56, Colm Bracken a écrit : > Hi All, > > I have a question, which is probably DSP 101 basics, but I just wasn't 100% > sure. > > If I am applying a 1024 point FFT to a continuous time-stream from an ADC > with sampling ~ 1 GSPS, I will have a time resolution ~ 1 microsecond (and > frequency res. of ~ 1 MHz). > > But, if I instead apply an 8 tap PFB, am I essentially smearing out my time > resolution by a factor of 8, since I am now summing 8 rows of my 1024 point > time streams? > I can't see how the number of PFB taps wouldn't affect my time resolution. Or > am I missing something? > > Thanks in advance, > Colm > > -- > > *Dr Colm Bracken* > Lecturer > Maynooth University Experimental Physics > > > Maynooth University, Maynooth, Co. Kildare, Ireland. > > T: +353 1 708 3641 > E: [email protected] <mailto:[email protected]> W: > www.maynoothuniversity.ie <http://www.maynoothuniversity.ie> > > Follow my work on https://nuim.academia.edu/ColmBracken > > > > And > > > Research Associate > > Astronomy & Astrophysics Section > School of Cosmic Physics > Dublin Institute for Advanced Studies > 31 Fitzwilliam Place > Dublin 2, D02 XF86 > > > > T: +353 1 440 6656 ext 352 > E: [email protected] <mailto:[email protected]> W: > www.dias.ie/2017/06/22/dr-colm-bracken > <https://www.dias.ie/2017/06/22/dr-colm-bracken> > > Follow my work on https://nuim.academia.edu/ColmBracken > > -- > You received this message because you are subscribed to the Google Groups > "[email protected]" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/CAEx9wh9GmrYZ7_uLkXwSKqOp3GYm1Ei_0Bq-TPg9pt8LgQdprw%40mail.gmail.com > > <https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/CAEx9wh9GmrYZ7_uLkXwSKqOp3GYm1Ei_0Bq-TPg9pt8LgQdprw%40mail.gmail.com?utm_medium=email&utm_source=footer>. -- Cedric Viou <[email protected]> Ingénieur de recherche Station de Radioastronomie de Nançay, Observatoire de Paris, PSL Research University, CNRS, Univ. Orléans, OSUC, 18330 Nançay, France http://www.obs-nancay.fr/ phone : +33 (0) 248 51 8609 fax : +33 (0) 248 51 8318 www.openstreetmap.org/?mlat=47.381848&mlon=2.194415&zoom=18 -- You received this message because you are subscribed to the Google Groups "[email protected]" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/68a23cbf-5320-8b50-7a4f-52379c4a2ad7%40obs-nancay.fr.
signature.asc
Description: OpenPGP digital signature
