| Description: | A Focal Plane Array (FPA), placed in the focus of a parabolic reflector, can be used to form multiple response beams on the sky by adding the signals from the array elements with different complex weight factors. The movie shows how the shape of the beam changes as a function of direction relative to the 'broadside' direction. It steps through a 5 x 5 grid on the sky in increments of about 0.5 deg, and shows the calculated/beamformed FPA voltage pattern (without the parabolic reflector) in each of the directions, in amplitude (left) and phase (right). Note how some of the phase patterns resemble a baboon, and others a koala. Reducing an observation taken with these things represents a bit of a challenge! |
