Hat Creek Radio Observatory | SRI International
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Hat Creek Radio Observatory

Hat Creek Radio Observatory is a cutting-edge radio astronomy, satellite tracking, and research services facility in a remote valley approximately 300 miles northeast of San Francisco, California. Surrounding mountains block interferences such as television and radio signals and cellular phone transmissions.

The observatory was founded by the University of California, Berkeley in the late 1950s. SRI International has managed the facility since 2012. The facility is available for use by the research community.  

The Observatory includes the Allen Telescope Array (ATA), a unique, flexible research instrument designed as a Large Number of Small Dishes (LNSD) array. Completed in 2007, the ATA was built by the SETI Institute and the University of California, with major funding from the Paul G. Allen Family Foundation. (View ATA specifications.)

The ATA is a 42-dish radio telescope that can operate as a snapshot camera, rapidly surveying large swaths of the sky. It operates over multiple frequency bands concurrently. The ATA can also operate as a single large dish (by pointing all dishes in the same direction) or as 42 independent dishes (looking in different areas of the sky simultaneously).

The site has the capacity to accommodate as many as 350 dishes.

Site elevation:  3235 ft.
Latitude:  40° 49' 03" N
Longitude: 121° 28' 24" W

Cost-Effective Resource for the Research Community

Hat Creek Radio Observatory is a significant resource for SRI’s clients and the research community at large. The Observatory offers highly automated, modular instruments. The facility’s resources may be operated remotely via the Internet, such as from SRI’s Menlo Park, California, headquarters.

Scientists and others can use it for cutting-edge research, such as:

  • Researchers can study space weather, polar weather, and solar weather, which can potentially harm power grids on earth or satellites in orbit, for advance planning that helps safeguard critical resources.
  • Post-doctoral students and professors can tap the ATA to conduct radio astronomy work.
  • Satellite operators often use the Observatory as a ground station for tracking CubeSats (small satellites used in space research, such as SRI’s Radio Aurora Explorer).  
  • The SETI Institute shares Observatory resources to conduct its own research programs to explore, understand, and explain the origin, nature, and prevalence of life in the universe. SETI also partners with institutions such as NASA to facilitate their research.

Additional Resources for Comprehensive Research

SRI’s Communications, Radar and Sensing Program operates the ATA. The group performs engineering research in radio astronomy, ionospheric phenomenology, radio communications (including CubeSat communications links), and signal processing.

SRI’s Center for Geospace Studies is a leader in the use of incoherent scatter radar (ISR) for remote atmospheric sensing research. The Center manages facilities for the National Science Foundation in Sondrestrom, Greenland; Arecibo, Puerto Rico; Poker Flat, Alaska; and Resolute Bay, Canada. These facilities offer SRI and other researchers several resources to fuse data sources and achieve a more holistic view of their data. Data are used by hundreds of scientists annually.

Visit Us

The Observatory is currently open for self-guided tours. Guided group tours require pre-arrangement. Learn more about visiting the facility.

News & Events

Allen Telescope Array close-up

SRI is the new manager of the Hat Creek Radio Observatory (HCRO) facility in Northern California, home of the Allen Telescope Array.