check aerostat blanking toward ao
Project a3460 is taking ips data during the covid
shutdown. Data from 24apr20 was used to check the aerostat blanking
in the ao direction.
The setup was:
- lband receiver covering entire band
- mock spectrometer with 7 80 Mhz bands
- 1 ms sampling, 16 bit spectra
- 3 min on , 3 min off source
The data processing was:
- Compute the total power over a 1 Mhz bw centered at
1261.2 (aerostat band) for the 1 ms samples
- Also compute a 50 Mhz total power bandwidth around 1480 Mhz to
The plots show the blanking of
the aerostat toward AO (.ps) (.pdf)
- Top: total power vs time for 12 second rotation.
- Black: this is the total power for the 1261 aerostat signal
- Red: the total power vs time for the 50Mhz about 1480Mhz.
- the vertical scale is 100*tsys + 10.
- The negative going spikes has the lbw band compressing.
- The blank region around 10 seconds is the aerostat blanking
- The blank region around 12 seconds is the aerostat blanking
toward the san juan airport.
- Bottom: blowup showing the blanking toward AO.
- The aerostat is blanking for 1.42 seconds or 42.6
degrees as it points at ao
- The blue line is where the mock spectrometer 16 bit spectra
- We can't tell if the blanking region is centered on AO since
the spectrometer has maxed out.
- Looking at the red 1480 Mhz compression, it looks like it
may be centered a little after AO (in the rotation).
- The aerostat blanking toward AO has remained the same.