SRI-Designed Radar System Signals New Age in Atmospheric Research; Prototypes in Peru and Alaska Help Scientists Understand Complex and Changing Upper Atmosphere.

MENLO PARK, Calif. -- With the unveiling of two Advanced Modular Incoherent Scatter Radar (AMISR) prototype systems, SRI International, an independent nonprofit research and development organization, today announced the latest milestones in the development of new upper atmospheric remote sensing capabilities. Chief among those milestones was the testing of the AMISR prototype systems at the Jicamarca Radio Observatory (JRO) in Peru and at the High Frequency Active Auroral Research Program (HAARP) Observatory in Alaska.

AMISR is a new concept in upper atmospheric radars being designed and built by SRI with funding from the National Science Foundation (NSF). SRI will build three AMISR antenna faces, each made up of 128 building-block-like panels. The first complete face is to be installed at Poker Flat, Alaska. When construction of the Alaskan facility is finished, two additional faces will be installed in Resolute Bay, Nunavut, Canada. When these two initial deployments are complete, NSF will determine subsequent locations based on input from the scientific community.

Though full AMISR radars have not yet been constructed, scientists are already using the AMISR prototype systems to conduct studies of the upper atmosphere and ionosphere. The complete systems will enable observations of the rapidly changing upper atmosphere and space weather events, which can interrupt satellite and electronic communications and even knock out earth-based electric power grids. Major blackouts caused by such grid failures can incur tremendous economic, public health and security risks.

The two field deployments demonstrate the modular aspects of AMISR's design in two very different environments. They also yield important scientific measurements of diverse phenomena in the ionosphere, a region of the earth's atmosphere where ionization caused by solar radiation affects the transmission of radio waves.

The eight-panel AMISR prototype installation in Peru is located at the Jicamarca Radio Observatory. The main purpose of installing AMISR at this location is to test its performance and to take advantage of the different capabilities of the system, which include electronic beam steering, wide angular illumination, UHF frequency and modular configuration.

Another eight-panel prototype of AMISR was deployed in Gakona, Alaska at the HAARP Observatory. This site was selected to field test AMISR hardware in an arctic environment and because it offers the rare opportunity to study ionospheric phenomena, such as the distortion of radio signals at high latitudes, that have the potential to alter the performance of communications and surveillance systems.

"Because the AMISR system is configured in modules, the facility can be routinely relocated for studying upper atmospheric activity around the globe," said John Kelly, program director at SRI's Center for GeoSpace Studies. "In addition, each of the three antennae faces of the AMISR system can operate together or be independently deployed in up to three separate locations. This facilitates comprehensive data gathering to increase our scientific understanding of upper atmospheric phenomena, which ultimately will help prevent the potentially large economic losses that result from severe space weather events."

Several companies are supporting the SRI-led project. These include subcontractor Sanmina-SCI, which manufactures the Antenna Element Units, the basic building blocks of the radar panels. VECO Alaska Inc. oversees design and structural engineering of the radar, including the panels and support scaffolding. MIT Millstone Hill is a co-investigator on the project.

More information about AMISR can be found at http://isr.sri.com/iono/amisr

About the AMISR System

Approximately the size of a football field when completed, AMISR is a modular, mobile radar facility with a radar beam that scientists can steer to observe and study upper atmospheric activity at various locations around the globe. A major benefit of the system is its ability to accurately measure rapidly changing space weather effects. The radar's modular design allows it to be disassembled and moved to study different types of upper atmospheric activity across the globe. No other radar of this size in the world can be routinely relocated.

About SRI International

Silicon Valley-based SRI International (www.sri.com) is one of the world's leading independent research and technology development organizations. Founded as Stanford Research Institute in 1946, SRI has been meeting the strategic needs of clients for almost 60 years. The nonprofit research institute performs client-sponsored research and development for government agencies, commercial businesses and nonprofit foundations. In addition to conducting contract R&D, SRI licenses its technologies, forms strategic partnerships and creates spin-off companies.