Antenna Sets and RCU Bands (Modes)
Antenna Sets
In international mode, we recommend using either the LBA_OUTER or HBA_JOINED antenna sets, depending on the part of the instrument you intend to use. The remaining antenna sets are mostly used in the core and remote stations depending on the needs of observers to full out different parts of the UV-plane when observing with multiple stations
LBA_OUTER can be used with bands 10_90 or 30_90, while HBA_JOINED can be used with 110_190, 170_230, 210_250. The properties of each of these bands are described below.
The choice of antenna-set and band in your beamctl command, with the --antennaset and --band flags will chose how the station operates.
RCU Bands (Modes)
The RCU band (formally known as RCU mode, now referred to as 'bands', configured via the --band flag) allows you to set the observing window for a given set of RCUs. While the band of each antenna polarisation can be configured to be independent on any other antenna (allowing for configurations such as KAIRA's Mode 3-5-7), we recommend only using a single observing band and use multiple observing epochs to see a source over multiple modes to allow for the use of the entire antenna set to maximise the sensitivity and keep a reasonable and predictable beam shape for each observation.
The name of each band roughly describes the frequencies at which the electronics will have a negligible effect on the observed data. Outside of these ranges, the Nyquist zone or other filters may suppress emission at certain frequencies, even if they are available at specific subbands.
Mode 0, 1, 2
These modes are the OFF, Low-band Low (200MHz) and Low-Band Low (160MHz) observation modes, they should not be be used on international stations and are meant to selectively use different parts of the array in the core and remote stations.
Mode 3 (Band '10_90')
Mode 3 is the standard LBA observing mode, using the entire set of LBA antenna and the 200MHz clock, covering 0MHz to 100MHz.
Mode 4 (Band '30_90')
Mode 4 enables observation with the entire set of LBA antenna and the 200MHz clock, with an additional high-pass filter to reduce the effects of bright signals below 30MHz, but allowing for observations from 0MHz to 100MHz.
Mode 5 (Band '110_190', "HBALo")
Mode 5 is the standard HBA observing mode, enables observing with the HBA tiles and the 200MHz clock covering 100MHz to 200MHz.
Mode 6 (Band '170_230')
Mode 6 enables observing with the HBA tiles and the 160MHz clock, covering 160MHz - 240MHz.
Mode 7 (Band '210_250', "HBAHi")
Mode 7 enables observing with the HBA tiles and the 200MHz clock. It has a reduced bandwidth compared to the other modes as a result of significant amounts of RFI and antenna attenuation being present above ~240MHz, but allows for observations from 200MHz to 250MHz.