Design and development of the MSA L-Band interferometer

Paper in proceeding, 2025

The Mauritius Small Array (MSA) is a novel prototype L-band radio interferometer (1420 MHz) developed at the Mauritius Radio Telescope (MRT) site as part of Africa's contribution to the Square Kilometre Array (SKA) midfrequency outstation initiative. The system comprises four 2.4 m parabolic antennas and serves as both a scientific and engineering testbed under the SKA Phase 2 programme. The primary science objectives of the MSA include investigating the large-scale spatial power spectrum of the Galactic HI distribution on angular scales from θmin ≈ 11.7^′ to θmax ≈ 90.6^′, and monitoring radio transients from the Southern Hemisphere. The array also contributes to improving the uv coverage between the South African SKA-Mid and the Australian SKA-Low arrays. From an engineering perspective, MSA enables the evaluation of mechanical mounting systems, optical alignment, structural resilience, and environmental survivability in regions prone to cyclones. This paper presents the design and development framework, with key aspects including wind load analysis, 3D CAD simulations, and performance testing of the 2.4 m dishes under extreme conditions such as Cyclone Batsirai (230 km/h) and Cyclone Freddy (256 km/h). The MSA design incorporates a Factor of Safety (FoS) of 5.178, which is approximately 159% more conservative than the typical range of 1.5-2.0 used for antenna reflector structures. Ongoing work explores scalable 12-element array configurations with dish sizes ranging from 2.4 m to 6 m, offering a compact and cost-effective alternative to traditional large single-dish systems for future SKA outstations.