Examining the sizes of the maximum beam sidelobes, it is found that both spiral versions have superior performance to the donut array. The first zoom spiral array is designed from the geometrically perfect shape plus random fluctations in position of each pad. Fig 1 Plan of zoom spiral array used for simulations. Mean baseline length is 941m and median is 875m. Cumulative distribution of uv points as a function of uv radius.
Yellow line shows best fitting gaussian uv density distribution.
Fig 2 Plan of optimised zoom spiral array used for simulations. Mean baseline length is 982m and median is 921m. Cumulative distribution of uv points as a function of uv radius. Yellow line shows best fitting guassian uv density distribution. Fig 3 Plan of donut-0.25 Kogan optimised array, scaled to have the same resolution as the zoom spiral in Fig 1.