| Description: | Thanks to the hard work of the CS1 commissioning team, we have working highband (HBA) tiles. Each tile consists of 16 dipoles in a 4x4 array. The above animation shows the (modelled) tile beam, as it is pointed at Cas A, during a 24 hour observation. The image is centered at the North Celestial Pole (NCP). As the sky rotates, the beam changes as the beamforming weights are adjusted to point to Cas A. The beams of the element dipoles are always pointed at the zenith, of course. In this image, the zenith traces the circle that passes close to Cas A.
The area in purple has zero gain and the area in red has the highest gain. As Cas A goes low in elevation, the beam gain towards it is also lowered, because of the element beam. The most interesting variation is in the sidelobe pattern. Note that Virgo A (bottom) passes through a strong sidelobe at one point, making it apparently stronger than Cyg A. |
