Open steven-murray opened 5 years ago
@lwhitler to chat with @adampbeardsley to figure out how to fix bug with xrfi
(xrfi
has no check
attribute) and to determine proper use of noise--does xrfi
expect a realistic level of noise, or does it just need enough noise to have finite chi-squared values?
What do you mean check
attribute?
xrfi
uses the noise to quantify the outlier-ness of data points. Having no noise will result in divisions by zero. Have unrealistic noise will result in unrealistic flagging. But if you abstract the performance in terms of SNR, I suppose any level should be ok. Of course the detrending of the actual signal isn't going to be perfect, so there will be some mutual coupling between noise and signal level, but I think that's second order.
@lwhitler can you post a screenshot of the error you showed in the telecon?
@adampbeardsley
If run_check=True
in xrfi.xrfi_run()
, this happens:
And run_check=False
is a different error:
Ah, this is an pyuvdata version issue. If you update pyuvdata (may need to do so from source, I'm not sure if it's in a release yet), you should be good to go.
This test is the first explicit test of
xRFI
. The idea is to usehera_sim
to add RFI to a fiducial simulation including EoR and FG, and then use xRFI to flag it, and then usepspec
to determine a power spectrum after flagging.hera_sim
,RIMEz
redcal
,smoothcal
,xRFI,
pspec`Why this test is required
21 and #22 check the performance of
pspec
with realistic flags (more realistic than this will generate), thus this is not a particularly good test of howpspec
deals with flags. What it adds is two things: 1) how wellxRFI
does in terms of accuracy of removing RFI, and 2) how much the inaccuracy propagates through to the power spectrum.Summary
A brief step-by-step description of the proposed test follows:
hera_sim.add_rfi
to add RFI visibilities (and save pure-RFI visibilities as well)redcal
andsmoothcal
.xRFI
xRFI
pspec
Simulation Details
Criteria for Success