MeerKAT

The MeerKAT array consists of 64 receptors with 13.5 m diameter dishes, designed to achieve high sensitivity and imaging dynamic range, while providing an array and functionality to provide for a wide range of science. MeerKAT achieves a sensitivity of at least 220 m2/K at L-band (our designs indicate that we may achieve 300 m2/K in the L-band). The high sensitivity requirement drives the design to multiple octave band single pixel feeds with cryogenic cooling. Three receivers cover the required operating band in the frequency ranges 0.58 - 1.015GHz, 0.9 - 1.67GHz and 8 - 14.5GHz. The receivers use Gifford-McMahon (GM) cryogenic cooling which will potentially significantly exceed the current sensitivity specification. The offset Gregorian dish configuration enhances sensitivity by providing high aperture efficiency and low spill-over temperature contribution. The offset Gregorian dish configuration also provides a clean optical path that can be designed to produce low overall sidelobe levels and azimuthal symmetry in the inner sidelobes to achieve high imaging dynamic range. Low sidelobe levels also provide good rejection of unwanted radio frequency interference from satellites and terrestrial transmitters. The array configuration is designed with two components: a compact core containing 70% of the dishes, and an extended array designed for high fidelity imaging performance over a range of resolutions from 6 arcsec to approximately 100 arcsec. 

 Antennas 64 Offset Gregorian
 Dish Diameter 13.5m
 Continuum imaging dynamic range at 1.4 GHz 60 dB
 Line-to-line dynamic range at 1.4 GHz 40 dB
 Mosaicing imaging dynamic range at 14 GHz 27 dB
 Linear polarisation cross coupling across -3 dB beam -30dB
 Sensitivity (0.58 – 1.75GHz) > 220 m^2/K
 Sensitivity (8 – 14.5GHz) > 200 m^2/K

Phasing:
 20112016 2018 
 PhasePrecursor (KAT-7) Phase 1 Phase 2 
 Number of dishes64 64 + 7
 
Receiver bands (GHz)
 
1.2 - 1.95
 
0.9 - 1.67
0.58 - 1.015
0.9 - 1.67
8.0 - 14.5
 Max processed bandwidth (GHz) 0.2560.75  2.0 (goal of 4.0)
 Max baseline (km) 0.185 8 20
 Min baseline (m) 26 29 29


MeerKAT Antenna Concept (click to enlarge):
 
 
 

MeerKAT Array Configuration

MeerKAT's 64 dishes will be distributed over two components:

  • A dense inner component containing 70% of the dishes. These are distributed in a two-dimensional fashion with a Gaussian uv-distribution with a dispersion of 300 m; a shortest baseline of 29 m and a longest baseline of 1 km.
  • An outer component containing 30% of the dishes. These are also distributed resulting in a two-dimensional Gaussian uv-distribution with a dispersion of 2 500 m and a longest baseline of 8 km.

For Phase 2, seven additional antennas will be added to extend the longest baselines to about 20 km. See attached files for spreadsheet (longitude, latitude and name) and Google Earth placemark locations of the 64 MeerKAT antennas for Phase 1.


Subpages (1): MeerKAT Science
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Jasper Horrell,
Jan 26, 2012, 5:33 AM
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MeerKATAntennas_64.kmz
(2k)
Jasper Horrell,
Jan 26, 2012, 5:41 AM