This cooperative agreement supported the operations and maintenance of major facilities used for upper atmospheric and space science. These facilities include two Advanced Modular Incoherent Scatter Radar (AMISR) instruments: the Poker Flat Incoherent Scatter Radar (PFISR) on the Poker Flat Research Range (PFRR) located north of Fairbanks, Alaska, and the Resolute Bay Incoherent Scatter Radar North Face (RISR-N) in Resolute Bay, Nunavut, Canada. This cooperative agreement also supported associated optical equipment in Alaska, and the operation of the Resolute Bay Observatory (RBO), which supports multiple other scientific instruments in addition to RISR-N.

Incoherent scatter radar (ISR) is a technique for studying the ionized portion of the upper atmosphere and near-Earth space environment, called the ionosphere. Incoherent scatter radars transmit high-power radio waves into the ionosphere and measure the properties of the weak radio waves scattered by ionospheric electrons. The AMISR instruments are electronically steerable phased-array radars that were specially designed for the NSF by SRI International. The AMISR design enables rapid sampling in different look directions, which allows for volumetric imaging of ionospheric parameters.

These facilities are multi-user facilities open to a broad array of academic researchers in domestic and international locations. During this award, SRI accepted requests for radar time from the community, worked with requestors to design experiments and coordinate observation campaigns, processed data, distributed data in community databases, and contributed to scientific publications using those data. Between 1 March 2012 and 31 March 2019, PFISR operated a total of 58,520 hours (94.3% uptime, average of 8,260 hours per year), and RISR-N operated a total of 13,020 hours (21.0% uptime, average of 2,509 hours per year). PFISR is operated nearly continuously using low-average-power modes between user-requested experiments. RISR-N only operates on a campaign basis because in that remote arctic site all the electricity must be generated with diesel generators.

The AMISR observational campaigns are frequently coordinated with instruments and missions funded by the NSF and other agencies, including NSF CubeSat missions, NASA suborbital sounding rocket missions launched from the PFRR, NASA satellite missions, and international satellite missions supported by the Canadian Space Agency, the European Space Agency, and the Japanese Aeronautics and Exploration Agency.

During this reporting period, data from facilities supported by this cooperative agreement contributed to 137 scientific publications, including nine Ph.D. dissertations and seven Master's theses. These publications cover a wide variety of topics in atmospheric and space science, including: the basic physics and chemistry of the ionosphere; magnetosphere-ionosphere coupling; the dynamics of electric fields in the ionosphere and their interaction with neutral winds in the upper atmosphere; the dissipation of energy in the ionosphere resulting in heating of the upper atmosphere; the ionospheric response to geomagnetic storms and other types of space weather; the physics of the aurora, particle precipitation, and energetic particle loss from the inner magnetosphere; effects of auroras and ionospheric structures on radio propagation through the ionosphere, including effects on Global Positioning System and other Global Navigation Satellite System signals; the basic physics of atmospheric winds, waves, tides, and turbulence; the atmospheric response to major atmospheric events such as sudden stratospheric warming events; plasma waves, instabilities, and related basic plasma physics; and the basic physics of meteors. These publications also cover developments in new radar signal-processing techniques and techniques for estimation and inverse problems.

The AMISR facilities are educational facilities in addition to research facilities. Many of the researchers requesting experiments and using the data are undergraduate students, graduate students, postdoctoral fellows, or early-career researchers. With support from this cooperative agreement, the science team at SRI has directly hosted and mentored two postdoctoral fellows, a visiting graduate student, and seven undergraduate students. This cooperative agreement also supported graduate students at Stanford University, the University of Washington, and the University of Alaska Fairbanks through subcontracts with those universities. Members of the SRI science team participate in an annual ISR summer school, which is a week-long intensive course for graduate students and advanced undergraduates providing hands-on training in the use of ISR data.

The AMISR program has also had a significant impact on technology transfer and space situational awareness. During this award, SRI developed the capability to track satellites with PFISR and to interleave commercial satellite tracking operations with the science operations on a non-interference basis. Aspects of the AMISR technology were incorporated into a SRI spin-off company, LeoLabs, Inc., which built new radars for commercial satellite tracking using aspects of the AMISR design. LeoLabs is now selling satellite tracking and other services to both government and commercial clients using their own radars and time purchased on PFISR that is interleaved on a non-interference basis with science operations.

Last Modified: 11/22/2019
Modified by: Roger Varney