Hat Creek Radio Observatory National Radio Dynamic Zone Prototype

This project enhances protection of radio astronomy facilities from radio frequency (RF) interference, and provides early lessons learned to inform the development of future National Radio Dynamic Zones that support a range of spectrum sharing needs. Currently, radio astronomy facilities and their observations are protected by prohibiting all transmissions in specific frequency bands, requiring other RF users to coordinate their operations in specific bands, or by designating radio quiet zones within which uncoordinated transmissions are prohibited at all frequencies.

However, increasing usage of the RF spectrum by wireless devices of all kinds is believed to be increasing the level of ambient RF noise. Further, the increasing demand for spectrum is forcing increased spectrum sharing between disparate radio services. New and innovative means are required to enable co-existence of radio astronomy facilities and other passive spectrum users with active services.

This project contributes to these challenges by: performing a systematic survey of RF noise at a representative radio astronomy observatory, the Hat Creek Radio Observatory in California; extending an existing commercial software product, the Google Spectrum Access System, to support spectrum sharing between communications and radio astronomy; testing the extended spectrum sharing software at Hat Creek; and exploring new approaches for bidirectional spectrum sharing between radio astronomy facilities and other users. Broader impacts of the project include techniques and standards for RF noise studies intended for broad adoption by the community; workshops on noise measurement and spectrum sharing that bring together radio astronomy and other communities while stimulating development of common solutions; informing regulators about the trades involved in spectrum sharing; and improving the ability of radio astronomy to operate in environments with large amounts of RF interference.

The project has four research thrusts. (1) Assess the RF environment at Hat Creek Radio Observatory to catalog, classify and identify the most significant interference sources. (2) Conduct a longitudinal RF noise survey, remotely managed, making all data openly available as a baseline for the broader research community, using a cloud-based architecture for data sharing that enables different privacy-protecting transformations on the raw data to be performed depending on the needs of the researcher. (3) Extend the existing Google Spectrum Access System software product to support automated radio astronomy spectrum coordination, covering 1 GHz to 15 GHz (work to be done by Google as an unfunded collaborator). (4) Examine new potential bidirectional spectrum sharing architectures starting from 3-Tier (operational in the US CBRS band), automated frequency coordination (planned for use in the US 6 GHz band), informing incumbent (proposed by US NTIA for future bands), and an Operations Research based theoretical approach. Results from the four thrusts will enable preliminary definition of the requirements and operating procedures for future National Radio Dynamic Zones, with a particular focus on evolution from current manual coordination processes to future automated mechanisms.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.