230627:pfb overflows with 3GHz band.



    Pulsar observations with the 3GHz filter (wb3) have seen lots of rfi in the 2750 to 3450 band (filter wb3). The rfi in polB is worse than polA.
The mock system log files

Show a large number of pfb (PolyphaseFilterBank) overflows. These are the butterfly stages in the fft.
This problem occurs because:

    On 27jun23 i took some data to see if a more aggressive pfb shifting would help the rfi situation.


Looking at the data:

File 000 with standard pfb pshift values

file 100 with the more aggressive radar shift for the pfb:

The first plot shows how often there were overflow errors in the two runs (.ps) (.pdf)

The next 2 images plot the total power vs time for the 5 bands:

The final image has the rms/mean by freq chan computed every 15.6 ms and the shown as a dynamic spectra (.jpeg)

processing: x101/230627/psr_pshift.pro


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