mhasself
commented
5 years ago On the first question, please go through @smsimon and the pwg:exm group (they are supposed to track the use of such parameters).
On the second question, I think I disagree with the consensus reached on that S4 page. The purpose of going from delta function bands to non-zero bandwidth is fully achieved by having almost any bandpass function with realistic width, because the point is just to make sure that you can handle the fact that different spectra pick-up differently across the band. The added realism of modeling idealized feed response (nu^-2) is, if I understand it, completely uninteresting.
Furthermore, saying that the bandpass is "top hat", and then defining that bandpass as nu^-2, seems like obfuscation. When we say "top hat", we conventionally mean a function that is 0, then 1 for a while, then 0. With the nu^-2 weight included in the definition of top-hat, if someone asks what the central frequency of the band-pass is, you have to say, "uh, what frequency?" because even if you've "centered" your top hat at nu_0, i.e. it's a band that's 0 except for inside [nu_0 - delta/2, nu_0 + delta/2]... the centroid (and thus plausibly the central frequency) is... and forgive-me-if-I-get-this-wrong-even-if-it-supports-my-point-to-do-so, ...:
ln( (nu + delta) / (nu - delta) ) * (nu^2 - delta^2) / 2 delta.
Blech.
zonca
smsimon
For the next TOD simulation, we would like to use top-hat bandpasses. All the map based simulations we have are delta-bandpass, I would like to run:
with top-hat bandpasses.
2 questions:
nu^-2