Two radio spectrometers with frequency coverage from 10 to 800 MHz will be constructed and deployed at the National Radio Quite Zone in Green Bank, WV. This effort, (i) develops a basic research tool in solar radio astrophysics for use by the wider community, (ii) remedies the lack of an important component of the United States National Space Weather Program: the need for readily available low-frequency, broadband, radio dynamic spectra in western longitudes, and (iii) provides a platform for research and development work on broadband antennas, feeds, and receivers operating from decimeter to decameter wavelengths. This program has important applications for instrument upgrades as well as future generations of instruments such as the LOw Frequency ARray (LOFAR) and the Frequency Agile Solar Radiotelescope (FASR).
The Green Bank Solar Radio Burst Spectrometer (GB/SRBS) is a an instrument designed to perform dynamic spectroscopy of energetic phenomena on the Sun at radio wavelengths. That is, it measures a record of the Sun's radio intensity from 10 MHz (30 m wavelength) to 1050 MHz (30 cm wavelength) once every second. Transient enegetic phenomena on the Sun such as flares and coronal mass ejections produce radio burst corresponding to distinct physical phenomena that produce unique radio signatures in radio dynamic spectra. For example, a beam of electrons produced by magnetic energy release produces a radio burst that drifts from high to low frequencies with time as the electron beam propagates from low in the corona to high in the corona. A shock driven be a CME produces a slow-drift radio burst that can serve as a proxy for the shock propagation. Radio dynamic spectroscopy is a valuable tools for basic research iproblens such as magnetic energy release, particle acceleration and transport, magnetohydrodynmic shock formation and propagation, and plasma processes. It is also a useful tool for detecting and monitoring space weather phenomena such as fast CMEs, which can have a broader impact on our technoligical society. SRBS was constructed with NSF support in the National Radio Quiet Zone at the National Radio Astronomy Observatory in Green Bank, WV. It has served not only as a tool for solar radiophysics, it has served as a platform for training undergraduate and graduate students, and as a platform for developingnew instrumentation (e.g., ultrawideband feeds and compact low-frequency rececivers). It is deployed as three separate antenna systems. The low-frequency system ranges from 10-80 MHz and is a standalone antenna. The mid- (110-350) system is feed by a log-periodic antenna mounted on the quadropod of a fully steerable 13 m telescope. The high frequency system (300-1050 MHz) is mounted at the prime focus of the 13 m telescope. The telecope tracks the Sun every day during daylight hours. The data are made available through a web interface where the spectra can be browsed or specific events can ve viewed. The data can be downloaded as images or as IDL save sets. Unfortunately, a storm seriously damaged the system in late 2012 and it was taken off line pending the availability of resources to repair and upgrade it. It is now nearing readiness to resume observations.
