Configuration #2 - Yagi Array (Current)
Two-by-Two Antenna Array
To increase the SNR of the received Vela Pulsar signals, it was decided to expand the single Yagi to a bay of 4 Yagis - in a 2x2 configuration.
Consideration was given to a 4x1 configuration - with the long dimension N-S to give the narrowest beamwidth dimension assigned to declination and the original single antenna beamwidth retained in the RA direction. This would mean the same time (2 hours) would be available for a drift-scan observation, but would require much greater care to ensure the declination pointing was correct. At the time it was considered a safer option to use a 2x2 configuration which would relax the declination pointing accuracy requirement, but allowing just 1 hour of drift-scan observation time.
The drop from a 2 hour observation drift-scan to a 1 hour observation was not - at the time - seen to be a disadvantage as the likelihood that a 'glitch' would occur in the 2 hour window out of 24 was only 1-in-10. This - as the 2019 glitch event showed - turned out to be both a good and bad decision.