Title: Interference Mitigation Tests at Molonglo Daniel Mitchell, Duncan CampbellWilson, Frank Briggs
1Interference Mitigation Tests at MolongloDaniel
Mitchell, Duncan Campbell-Wilson, Frank Briggs
2Overview
- RFI mitigation is likely to play an important
role in SKAMP data processing. - The wide bandwidth alone will open the telescope
up to a much greater level of RFI. - Have done some short, preliminary observations
with and without RFI to see how effective
mitigation is likely to be.
3Preliminary RFI Tests.
- MOST has 88 bays (antennas), which will be
cross-correlated with all of the others - 88 input correlator.
- Correlator will have 96 inputs
- Room for RFI reference antennas.
- Use closure relation based "post-correlation"
cancellation algorithm to test RFI reduction.
4RFI Test Range
- RFI - Broad-band noise from the RFI site
- Estimated 5000 computer equivalents
- Telemetry link to transmitter, variable
attenuator white noise source - 4 IFs Sampler box
- Two 778m x 12m MOST arms (with bay masking)
- Two orthogonal polarisations from the 6m dish
- Record to a PC at 16 Msamples / second / IF
5Short Baselines (bays E01 W01)
6Short Baselines (bays E01 W01)
7Short Baselines (bays E01 W01)
8Short Baselines (bays E01 W01)
9Short Baselines (bays E01 W01)
10Short Baselines (bays E01 W01)
11Medium Baselines (bays E22 W22)
12Medium Baselines (bays E22 W22)
13Medium Baselines (bays E22 W22)
14Long Baselines (bays E44 W44)
15Long Baselines (bays E01 W01)
16Long Baselines (bays E01 W01)
17Summary
- RFI mitigation is likely to play an important
role in SKAMP data processing. - The wide bandwidth alone will open the telescope
up to a much greater level of RFI. - A preliminary look at cancelling RFI from single
bay cross-correlations seemed to work well on
three baseline scales.