SRI creates sophisticated, low-cost, fault tolerant, phased array radars providing unprecedented Geospace monitoring


A cost-effective, scalable, and modular alternative to both traditional dish and, ultra-expensive, array-radar systems.


Companies don’t have a reliable way of Incoherent scatter radar is the most capable ground-based tools for monitoring and measuring the Earth’s ionosphere and upper atmosphere. Existing systems are large, expensive, power-hungry, and high maintenance restricting them to only a few sites around the world.


Researchers at SRI International created AMISR (the advanced, modular, incoherent scatter radar). AMISR is a phased array technology that is a cost-effective, modular, and scalable alternative to traditional incoherent scatter radars. With no moving parts and no dangerous high voltages, AMISRs can operate around the clock, even in harsh, remote and unattended conditions.

Space and Geospace research often require researchers to invest in expensive equipment, but restricted funding frequently forces unfortunate compromises. Deployed examples of even the most effective technologies, such as incoherent scatter radars, are often limited in capability: for example, by temporal-spatial ambiguities that force scientists to make assumptions when interpreting their measurements.

To improve these research capabilities, SRI launched the AMISR (advanced, modular, incoherent scatter radar) project in the early 2000s. By carefully exploiting commercially available components, coupled with high-quality engineering and attention to costs, AMISR brings high-power, flexible, phased array technology within the financial grasp of academic researchers and other non-defense related and commercial users. AMISR is a phased array system built with a modular architecture that provides scientists with a cost-effective and scalable alternative to traditional radar systems.

Phased array radars achieve beam-steering electronically without the need for large, heavy, slow-moving antennas and enable researchers to gather measurements in multiple directions, and of multiple types, simultaneously. Amongst other things, AMISRs can perform ionospheric imaging and gather precise, three-dimensional measurements of plasma convection velocities, both of which are essential to understanding the physics and behavior of the geospace environment.

In addition to being an improvement over traditional radar technology, AMISR also is the first incoherent scatter radar for which:

  • The design has been replicated in multiple deployments.
  • The system has been sold as a commercial project.
  • The system has been sold to a foreign country.

AMISR also is the first incoherent scatter radar ever to achieve long-term, routine, continuous operation (that has continued for well over 10 years). This reliability is just one of the aspects that caused AMISR ideas to drive the creation of a new, European, phased array research radar currently under development/construction by the EISCAT Scientific Association.

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