puppi was setup to run with the 1-2 ghz vlbi
The rf center frequency was 1650 Mhz (putting 1350 Mhz at the
center of the puppi band). The 1370Hipass filter was used.
Puppi was run in 800 Mhz search mode (IQUV).
show the recorded spectra (.ps)
The 1550 Mhz is caused by the power levels being way to low
- The data came from file:
- Top: Stokes I 4 second average spectra.
- The drop at 1370 Mhz is from the 1370 hipass filter
- The step at 1550 Mhz was a bit of a mystery.
- Bottom:single 1.024 Millisecond spectra.
- + have been used to show the steps in the data.
- The range 1370 - 1550 only have 2 a/d counts
- the range 1550-1750 only have a single a/d count..
Other things to watch out for.
- When puppi does the if/lo setup, it sets lbw to
- vlbi wants circular polarization.
- so you need to make sure that lbw pol is set back to
circular after the puppi setup.
- This means that the puppi header will say IQUV,
when it will probably be IVUQ (with probably a
pretty lousy V).