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<tt>Hi Evan, all,<br>
<br>
Apertif uses the same PFB and there too Eric Kooistra and I looked
into it. The filterbank is critically sampled as Ben writes, which
is an issue. One more problem (depending on the stage at which you
want to the inversion) as that you need all the subbands to go
back, so after subband selection you have an information deficit.
Eric most likely has a Matlab model. <br>
<br>
Cheers,<br>
Joeri<br>
<br>
==<br>
<br>
</tt><br>
<div class="moz-cite-prefix">On 11-6-2020 09:57, Benjamin Stappers
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:4186583B-CB39-49A8-8A44-12E109CAC645@manchester.ac.uk">
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Hi Evan,
<div class=""><br class="">
</div>
<div class="">I don’t have anything quickly to hand, but I can
take a look. On the inversion,</div>
<div class="">we looked into some of this a long time back for the
Cosmic Ray work and </div>
<div class="">I believe that there was a student, I could find out
her name and details who</div>
<div class="">worked on that. However, my memory is such that
while it is possible in theory</div>
<div class="">it isn’t actually possible unless you do a
oversampled polyphase like the ASKAP</div>
<div class="">one and the one proposed for SKA-Low. </div>
<div class=""><br class="">
</div>
<div class="">Cheers - Ben</div>
<div class=""><br class="">
<div><br class="">
<blockquote type="cite" class="">
<div class="">On 11 Jun 2020, at 08:52, Evan Keane <<a
href="mailto:evan.keane@gmail.com" class=""
moz-do-not-send="true">evan.keane@gmail.com</a>>
wrote:</div>
<br class="Apple-interchange-newline">
<div class="">
<div dir="ltr" class="">Hi PWG,
<div class=""><br class="">
</div>
<div class="">Does anyone have to hand a
paper/document/anything describing the LOFAR polyphase
filterbank in the RSP boards, or a model for them? The
kind of thing I could run on (say) some simulated
Nyquist voltages to get a LOFAR RSP like response?
And, related, any attempts to invert the polyphase
filterbank?</div>
<div class=""><br class="">
</div>
<div class="">Evan</div>
<div class="">
<div class=""><br class="">
</div>
-- <br class="">
<div dir="ltr" class="gmail_signature"
data-smartmail="gmail_signature">
<div dir="ltr" class="">
<div class="">
<div dir="ltr" class="">Is mise le meas,<br
class="">
Dr. E. F. Keane
<div class="">
<div class=""><br class="">
<div class="">**Smaoinigh ar an
timpeallacht - an gcaithfidh tú an
r-phost seo a phriontáil?**<br class="">
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<div>***************************************************************</div>
<div>Ben Stappers</div>
<div>Head of Pulsar and Time Domain Astronomy Group</div>
<div>MeerTRAP Project Lead</div>
<div>Jodrell Bank Centre for Astrophysics</div>
<div>Department of Physics and Astronomy</div>
<div>The University of Manchester</div>
<div>Phone: +44 161 2754187</div>
<div>***************************************************************</div>
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