The alfa bandpass for beam0
was measured using the mock spectrometers. The setup was:
- two mock bands were used.
- Each band has 172 Mhz bandwidth
- cfr: 1300, 1450
- Edge of band: 1214Mhz, 1535 Mhz
- The band edges of the mock spectrometer will define the
range we can measure.
- The winking cal was used with .25 secs on, .25 secs off
for 3 seconds
The plots show the uncalibrated and
calibrated bandpass (.ps)
- Top: uncalibrated bandpass
- This shows the two mock bandpasses.
- Black is polA, red is polB
- Each bandpasses was normalized to the median value.
- Bottom: bandpass in degK.
- Caldif=calOn-calOff was divided into the calOff
- This removes the downstream bandpass and converts to
- The calvalue (as a function of freq) was then multiplied
to get Tsys.
- I then used a median filter of 9 to smooth the band.
- The ripple (especially in polB) has a period of about 60
Mhz. This is 2.5 meters in free space.
The bandpass is probably defined by the 1220 to 1520
filter seen in dana's