Astrophysics Group

Cavendish Laboratory

AMI Technical Information

Each of the AMI arrays observes using a nominal 6-GHz bandwidth centred at 15 GHz. The band is divided into eight equal-bandwidth channels of 0.75 GHz. However, the two lowest frequency channels are not ordinarily used, owing to contamination from geostationary satellites. Therefore, the six usable channels span frequencies from 13.5 to 18 GHz. The table below contains some key technical information for each of the arrays. A detailed description of AMI can be found in AMI Consortium: Zwart J. T. L. et al. (2010). We are always interested in opportunities to collaborate; if you have ideas for potential projects involving AMI please contact the project manager, Richard Saunders.
Small Array Large Array
Number of antennas 10 8
Antenna diameter 3.7 m 12.8 m
Antenna efficiency 75% 67%
Antenna mount Equatorial Equatorial
Baseline lengths 5 to 20 m 18 to 110 m
Primary beam (15.7 GHz) 20.1 arcmin 5.5 arcmin
Synthesised beam ≈ 3 arcmin ≈ 30 arcsec
Polarisation measured Stokes I + Q Stokes I + Q
Flux sensitivity 30 mJy s-1/2 3 mJy s-1/2
Declination range > -15° > -20°
In practice we rarely observe below declination +20° because of interference from satellites.