Owens Valley Solar Arrays (OVSA) is a university-led radio facility dedicated to solar astrophysics and space weather research. Located in the Owens Valley Radio Observatory (OVRO) near Big Pine, California, the operations of OVSA include the Expanded Owens Valley Solar Array (EOVSA) observing in the microwave regime (1-18 GHz), as well as the solar and space weather aspects of the newly commissioned Long Wavelength Array at the Owens Valley Radio Observatory (OVRO-LWA), which observes in the meter-decameter wavelength regime (13-87 MHz).

EOVSA operations are led by the New Jersey Institute of Technology (NJIT), joined by the California Institute of Technology (Caltech) and University of California, Berkeley. It makes daily observations of the Sun at microwave frequencies (1-18 GHz) with simultenous imaging and broandband spectroscopy, addressing a broad range of scientific topics in the low solar atmosphere. EOVSA was the result of a major expansion of our legacy array, a project funded by NSF using American Recovery and Reinvestment Act (ARRA) funds and completed in 2017. Currently, EOVSA is being upgraded again by replacing all the remaining old equatorial antennas with new azimuth-altitude-mounted antennas, adding two new antennas to the array, and equipping all antennas with new-generation quad-ridge flare feed horns. The upgrade project (EOVSA-15), supported by the NSF Major Research Instrumentation (MRI) Program (AGS-2320478), will create a 15-element array with full imaging spectropolarimetry capabilities and enhanced imaging performance. The upgrade project is expected to complete in 2026.

OVRO-LWA is a multi-institutional project led by Caltech, with its operations relevant to the solar and space weather aspects led by NJIT. After its recent completion (funded via NSF's MRI program AST-182784), the array now consists of 352 cross-dipole antennas spanning a footprint of 2.4 km. OVRO-LWA is a highly versatile, multi-use system. It observes the full-sky at meter-decameter wavelengths (13-87 MHz), with science topics spanning from solar and space weather science to exoplanets and cosmology. For solar observing, this wavelength regime probes the Sun's "middle corona," loosely defined as the region between ~1.5 and 10 solar radii. A public release of the OVRO-LWA solar data is expected in the summer of 2025.

The OVSA project aims to support the community by providing open data access and software tools for analysis of the data, to exploit synergies with on-going solar research in other wavelength bands, and to train next-generation scientists. OVSA operations are mainly supported by NSF under the Geospace Facilities program through NSF Award AGS-2436999, and receives additional support from NASA's HSO Data Support program under grant 80NSSC20K0026.

The range of science to be conducted with OVSA is broad and unique. A list of publications that utilized OVSA data is available at this NASA/ADS Library. Check out the science page for more on each topic.

• Magnetic and Plasma Structure Above Active Regions
  • Coronal Magnetography
  • Coronal Temperature, Density, and Abundance
• Magnetic Energy Release and Particle Acceleration
  • Measuring Magnetic Fields in Solar Flares and Coronal Mass Ejections
  • Particle Acceleration and Transport by Flares and Coronal Shocks
• Coronal Heating and Solar Wind Acceleration
  • Weak Microwave Coronal Transients
  • Weak Radio Bursts in Middle Corona
• Drivers of Space Weather
  • Near-realtime Mapping of Coronal Mass Ejections in Radio
  • Realtime Observations of Solar Radio Bursts
  • Daily F10.7 Images