23jun20 lbw rfi using puppi



the average  data: spectra and total power for 83 seconds (.ps) (.pdf)
dynamic spectra using  .17 average spectra (.png):
Hires total power vs time and the  power from the 4 radars radars (.png)
Hires total power vs time for each radar
Dynamic spectra with 240Usec resolution at deepest compression (.png)
Dynamic spectra with  40usec resolution during  compression (.png)
7 40 usec spectra from within the 78.9725 sec compression (.ps) (.pdf)
gns satellite passes over AO during the observation.

83 second movie of the dynamic spectra (.167 sec resolution)  (.avi) (290MBytes)


    Project p2789 was running puppi in pulsar search mode using the lbw receiver on 23jun20 from 00:30 am to about 3am. They reported that more than 50% of the band was corrupted with rfi.
    Their  setup was:

To debug the problem i looked at file


which started at 23jun20 00:52:12 AST.
The first few minutes of the file were used.
The telescope was located at az=346 and za=13.2 (looking south)

Plotting the average spectra and total power:

    Each row in the fits file had 4096 spectra (40Usec each). I computed the average spectra for 500 rows (83.8 seconds of data).

The first plots shows the average data (.ps) (.pdf)

    The Average spectra has lots of small  spikes in it.

Dynamic spectra of .17 sec spectra

    A dynamic spectra image was made using the .17 average spectra (.png):

Total power vs time

    The first summary plot shows the total power vs time and the  power from the 4 radars radars (.png)
The 2nd set of plots is a blowup showing the total power and a single radar power:

totPwr and AeroStat (.png)
totPwr and PuntaBorinquen (.png)
totPwr and FAA (.png)
totPwr and PuntaSalinas (.png)

Dynamic spectra blowup at deepest compression

    One row of data from the fits file (.167 secs, 4096 spectra) at the deepest compression (row 470.. cnt from 0.. @ 78.93 seconds) was used to look at the affects of compression.

    The dynamic spectra shows the .167 seconds of data (.png)

A second dynamic spectra blowup using 9 milliseconds of time about 78.973 secs was made (.png)

7 40 usec spectra from within the 78.9725 sec compression  were plotted (.ps) (.pdf)

The Global Navigation satellites

    The row averaged (.167) dynamic spectra showed wide rfi at some gns bands:

plots were made of the various satellite constellations positions relative to AO on 23jun20 1:00


Plot  description:

During the 89 secs of the dynamic spectra the telescope was at  az=346, za=13 (looking south).
Satellitesthat could have caused what we saw:


    What can be done:
processing: x101/200630/doit.pro

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