A Solar-Dedicated Instrument for Real-Time Meterwave Radio Spectral Imaging

The Owens Valley Radio Observatory Long Wavelength Array (OVRO-LWA), an all-sky imager operating in the range 13-88 MHz, is now operating with longer baselines and a new solar-dedicated backend to provide commensal daily solar imaging observations. The 352 antenna elements provide baselines to 2.6 km (5 arcmin resolution at 80 MHz). Modes include (1) a solar-dedicated beam with 3072 frequencies (24 kHz resolution) measured simultaneously over 13-88 MHz at 1 ms time resolution, (2) a slow-visibility interferometric imaging mode with 10 s time resolution on all baselines for extremely sensitive imaging of slowly varying emission, and (3) a fast-visibility interferometric imaging mode at 0.1 s time resolution on baselines of 48 selected antennas for stronger bursts of more rapid variability. A near-real-time pipeline producing ultra-high-sensitivity spectrograms and images within minutes is now operational at https://ovsa.njit.edu/status.php. Even lower-latency data products are feasible with more computing resources, if determined to be useful for operational purposes.