SOLARIS (“A smart Solar imaging system at high radio frequency for continuous Solar monitoring and Space Weather applications”) is a scientific and technological initiative led by the Istituto Nazionale di Astrofisica (INAF) in collaboration with Italian and international research institutions. The project’s overarching goal is to design, construct, and deploy a high-frequency solar radio imaging system capable of continuous monitoring of solar activity, with particular relevance to space weather forecasting and solar physics research.
The project focuses on the development of a single-dish radio imaging instrument operating at approximately 100 GHz, a frequency regime that offers unique diagnostic capabilities for the solar chromosphere and lower corona. Unlike existing facilities that primarily observe at lower radio frequencies or rely on large interferometric arrays, SOLARIS adopts a compact and modular design to enable easier deployment and maintenance. This approach allows the system to achieve high temporal coverage and operational flexibility, making it suitable for continuous observations of dynamic solar phenomena.
A key innovation of SOLARIS lies in its proposed deployment at extreme sites, particularly in Antarctica, where the long summer daylight periods and low atmospheric water vapor content provide optimal conditions for high-frequency radio observations. Additional prototype and testing facilities have been established or planned in Milan, at Alpine sites such as Testa Grigia, and at northern hemisphere locations, with the ultimate goal of creating a global network of observatories enabling year-round solar coverage.
Scientifically, SOLARIS aims to fill an observational gap in solar monitoring by providing continuous, high-frequency radio imaging to study both quiescent and active solar regions. The system is designed to investigate a broad range of solar phenomena, including the spectral variability of active regions, flare dynamics, precursor signatures of solar eruptions, and non-thermal emissions. These observations are expected to enhance our understanding of the energy release processes in the solar atmosphere and to contribute to predictive models of space weather that affect Earth’s technological infrastructure.
From a technical perspective, SOLARIS builds upon existing small radio-telescope infrastructures (1.5–2.6 m class) by integrating state-of-the-art high-frequency receivers inspired by technologies used in instruments such as ALMA. This configuration ensures both cost efficiency and adaptability, while maintaining the sensitivity required for detailed solar imaging at millimeter wavelengths.
The project, initiated around 2023, is supported by Italian national funding programs, including the Programma Nazionale di Ricerche in Antartide (PNRA), and has an anticipated duration of approximately four years. Its phased implementation includes laboratory development, alpine and polar field testing, and eventual full deployment at selected sites.
In summary, SOLARIS represents an ambitious step toward establishing a continuous high-frequency solar monitoring infrastructure. By combining advanced radio instrumentation, strategic polar deployment, and interdisciplinary scientific goals, the project seeks to advance both fundamental solar physics and the practical field of space weather monitoring.
Further information on the SOLARIS official website:
Referents:
- prof. Marco A. C. Potenza, marco.potenza@unimi.it
- Massimiliano Oranges, massimiliano.oranges@unive.it
- Elena Vignati, elena.vignati@unive.it