Initial results from Poker Flat Incoherent Scatter Radar (PFISR)

The Advanced Modular Incoherent Scatter Radar (AMISR) is a phased array incoherent scatter radar (ISR) strategy with unique modular features that allow efficient and cost-effective dismantling, shipping, and re-assembly. The current AMISR comprises two identical radar antenna faces, each with approximately three times the sensitivity of the Sondrestrom incoherent scatter radar currently operating in Greenland. Each of the fixed antenna faces is approximately 30 m with 4096 radiating elements located on 128 separate panels. The first of these faces was completed in December 2006 at the University of Alaska’s Poker Flat Research Range, located approximately 30 miles north of Fairbanks, Alaska. This AMISR face has been named PFISR—Poker Flat Incoherent Scatter Radar. PFISR provides the means for unique scientific observations via two significant features that have not been technically feasible in the past and that greatly enhance the way observations and experimental campaigns are conducted. First, the phased array concept allows pulse-to-pulse beam steering, thus enabling threedimensional ‘‘imaging’’ of electron density features in high signalto-noise environments. Second, an incoherent scatter radar with a solid-state transmitter and no moving parts permits both extended operating periods and true remote internet operation with virtual ‘‘control rooms’’ at locations worldwide. Indeed, during the 2007–2008 IPY, PFISR operated essentially 24/7 without on site personnel for 22 months. The great utility of these continuous operations, as evidenced in part by papers in this special issue, has prompted an effort to continue this beyond the end of the nominal IPY period. PFISR uses advanced solid-state amplifiers and electronics that can be computer-controlled for maximum flexibility and ease of use. It provides outstanding opportunities for students and young scientists and engineers to be involved with the development of the project and the operation of the instrument. Finally, the AMISR project is the first National Science Foundation (NSF) Upper Atmospheric Facility that was designed,