# What is the role of the mesh on which dipole elements of the MWA antennas are placed?

I was reading about the radio telescope - Murchison Widefield Array (MWA) situated in Western Australia. Antennas of this telescope are quite unique and different from the usual dish radio telescope. In MWA a four by four regular grid of dual-polarisation dipole elements are arranged on a 4m x 4m steel mesh.

So, I was wondering why these dipole elements would have been mounted over the mesh? On searching over internet I found out that this mesh is called a counterpoise (though I am not sure if I am correct). I read more about it and I partially understand that the mesh and ground (Earth) act as two plates of a capacitor but I didn't get why it was done and what was the use of it? In this image mesh can be seen on which dipole are mounted - Image courtesy: SKA

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• +1 Speculation; for a simple dipole a good ground plane spaced at the right distance will increase the gain by 3 dB. The Earth here looks dry and the wavelength is short so it will not be a proper ground plane. However a ground plane will modify both the directionality and the frequency response as well, so I think a good answer will address the optimization of this 70 to 300 MHz design, including why each polarization has three inclined dipoles. (I'm guessing that makes it less directional so a wider field in the sky is received). – uhoh May 25 '20 at 1:42
• Also note that array will be made of many of these "tiles" spaced out in a complex pattern over large distances. – uhoh May 25 '20 at 1:42
• counterpoise vs ground: 1, 2, 3 and The Murchison Widefield Array: Design Overview which mentions the wide angular acceptance: "covering that area of ground with antennas sensitive to the entire 2-pi steradians of the sky" and calls it a "ground plane". – uhoh May 25 '20 at 1:58