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Yesterday's ADAP showed pulsar profiles as a function of frequency
across the Parkes Murriyang Ultra-Wideband Low (UWL) receiver, which covers
frequencies from 0.7 to 4.0 GHz.
The overall contamination of the band by Radio Frequency Interference (RFI)
is relatively low, and the two most significant sources of
RFI being mobile phone (below 1000 MHz) and WiFi/Bluetooth (~2400 MHz)
transmissions.
(It should be noted these are licensed users of these frequency bands,
and it is the sensitive nature of the wideband receiver that detects
these signals.)
Today's ADAP contrasts UWL spectra taken during the day (left) and at night (right).
Not surprisingly, during the night the mobile phone signals and wifi/bluetooth
signals are significantly reduced, but other sources such as global positioning
system satellites are unchanged.
The regularly spaced dips across the band are a feature of how the wideband
data is processed. The lower power levels in the lowest ~20% of the band
arise because the mobile phone signals are the strongest RFI received
and so some extra attenutation has been added in this portion of the band.
(Image credit: George Hobbs)
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