Rfi with the 12meter.
last updated 23sep21
210908: 8330 Mhz rfi
On 8sep21 crosses were done on 3C273
with the 12meter using xband (for pointing model). The setup was:
- Az,El strips of 1.2 degrees were done (2 minute each).
- The mock spectrometer was used to record spectra:
- .1 sec integration
- 172.032 Mhz bw, 1024 channels
- Tbe band centered at 8350 Mhz showed rfi. This rfi was often
To process the data.
- The average specdtra was computed for each 120 strip.
- the rms/mean by freq channel was computed for az strip
- the source deflection did not skew the rms/mean much as we
drove over the source.
The plots show the rfi seen 8319 to 8349 Mhz
- Top: average spectra for each 120 second strip (105 in total)
- Black in polA, red is polB
- The purple lines flag the limits of the rfi: 8319 to 8349
- Bottom: rms/mean by freq channel for each 120 second strip.
- there are 1200 .1 second samples in each strip.
- The expected rms/meanis : 1/sqrt(168e3*.1) = .008. The green
line shows this value.
- There are large deviations in the 8319-8349 Mhz section of
- rfi was seen between 8319 and 8349 Mhz
- This rfi was seen every day the model 4a data was taken.