Hybrid ADS-based techniques for radio astronomy array design

A set of techniques are presented that are based on the exploitation of low correlation sequences called Almost Difference Sets (ADSs) to design correlator arrays for radio astronomy applications. Three approaches are discussed with different objectives and performances. ADS-based analytical designs, GA-optimized arrangements, and PSO optimized arrays are presented and applied to the synthesis of open-ended “Y” and “Cross” array configurations to maximize the u - v coverage or to minimize the peak sidelobe level (PSL). Representative numerical results are illustrated to point out the features and performances of the proposed approaches, and to assess their effectiveness in comparison with state-of-the-art design methodologies, as well. The presented analysis indicates that the proposed approaches overcome existing PSO-based correlator arrays in terms of PSL control (e.g., > 1.0 dB reduction) and tracking u-v coverage (e.g., up to 2% enhancement), also improving the speed of convergence of the synthesis process.