On 01mar16 simultaneous data was taken
with the sb and xb receivers on the 12 meter telescope.
The setup was:
- sband:
- polA fiber rcvr (upper most)-> amp -> mixer (2270
to 325MHz) -> amp -> filter -> amp -> mock
mixer -> mock spectrometer
- cfr 2270 MHz, bw: 172 MHz
- xband:
- polB fiber rcvr -> udc(1.5-2GHz output) -> mixer
(udc out to 325 MHz) -> mock mixer -> mock
spectrometer
- cfr 8600 MHz, bw: 172 MHz
- Mock spectrometer:
- 1 second dumps, 172.032 MHz bw, 8192 channels
2 hours of data were taken. When looking
at the sband spectra, a change in the band pass shape with
time was seen.
To demonstrate the shape change:
- 10 spectra spaced by 630 seconds each were selected.
- Each of these spectra were normalized to their median
value.
Plots of the 12meter
spectra covering 6300 seconds (.ps) (.pdf)
- Page 1: sband spectra
- Top frame: the 10 spectra over plotted (each with a
separate color). The vertical scale is Tsys.
- Middle frame: spectral change from 1st spectra
- the plots show: spectra[*,i*630] -
spectra[*,0] the change in the spectra
- black is the first difference. yellow is the last
- bottom frame: spectral change (with offsets for display)
- Same as the middle frame, but offsets have been added
for display.
- the black bottom difference is spc(*,630) -
spc[*,0]
- dashed lines show the baseline of each difference.
- Page 2: xband spectra
- the 10 xband spectra were over plotted. They show no
spectral shape change.
processing: x101/160301/p12m_spectra.pro