M. R. Negale, M. J. Taylor, M. J. Nicolls, S. L. Vadas, K. Nielsen, and C. J. Heinselman. Seasonal propagation characteristics of MSTIDs observed at high latitudes over Central Alaska using the Poker Flat Incoherent Scatter Radar. Journal of Geophysical Research: Space Physics, American Geophysical Union, volume 123, 2018 . T. Valentic, J. Buonocore, M. Cousins, C. Heinselman, J. Jorgensen, J. Kelly, M. Malone, M. Nicolls, and A. van Eyken. AMISR: The Advanced Modular Incoherent Scatter Radar. 2013 IEEE International Symposium on Phased Array Systems and Technology, 2013 . D. Hysell, R. Miceli, J. Munk, D. Hampton, C. Heinselman, M. Nicolls, S. Powell, K. Lynch, and M. Lessard. Comparing VHF coherent scatter from the radar aurora with incoherent scatter and all-sky auroral imagery. J. Geophys. Res., volume 117, 2012 . H. Dahlgren, G. W. Perry, J. L. Semeter, J.-P. St.-Maurice, K. Hosokawa, M. J. Nicolls, M. Greffen, K. Shiokawa, and C. Heinselman. Space-time variability of polar cap patches: Direct evidence for internal plasma structuring. J. Geophys. Res., volume 117, 2012 . H. Dahlgren, J. L. Semeter, K. Hosokawa, M. J. Nicolls, T. W. Butler, M. G. Johnsen, K. Shiokawa, and C. Heinselman. Direct three-dimensional imaging of polar ionospheric structures with the Resolute Bay Incoherent Scatter Radar. Geophys. Res. Lett., volume 39, 2012 . M. J. Nicolls, D. C. Fritts, D. Janches, and C. J. Heinselman. Momentum flux determination using the multi-beam Poker Flat Incoherent Scatter Radar. Ann. Geophys., volume 30, issue 6, pages 945-962, 2012 . H. Akbari, J. L. Semeter, H. Dahlgren, M. Diaz, M. Zettergren, A. Strømme, M. J. Nicolls, and C. Heinselman. Anomalous ISR echoes preceding auroral breakup: Evidence for strong Langmuir turbulence. Geophys. Res. Lett., volume 39, 2012 . J. J. Sojka, M. Nicolls, A. van Eyken, C. Heinselman, and D. Bilitza. 24/7 Solar minimum polar cap and auroral ion temperature observations. Advances in Space Research, volume 48, 2011 . R. H. Varney, M. C. Kelley, M. J. Nicolls, C. J. Heinselman, and R. L. Collins. The electron density dependence of polar mesospheric summer echoes. J Atmos Sol-Terr Phy, volume 73, 2011 . L. R. Lyons, Y. Nishimura, H.-J. Kim, E. Donovan, V. Angelopoulos, G. Sofko, M. Nicolls, C. Heinselman, J. M. Ruohoniemi, and N. Nishitani. Possible connection of polar cap flows to pre- and post-substorm onset PBIs and streamers. J. Geophys. Res., volume 116, 2011 . S.-R. Zhang, J. M. Holt, A. P. van Eyken, C. Heinselman, and M. McCready. IPY observations of ionospheric yearly variations from high- to middle-latitude incoherent scatter radars. J. Geophys. Res., volume 115, 2010 . L. R. Lyons, Y. Nishimura, Y. Shi, S. Zou, H.-J. Kim, V. Angelopoulos, C. Heinselman, M. J. Nicolls, and K.-H. Fornacon. Substorm triggering by new plasma intrusion: Incoherent-scatter radar observations. J. Geophys. Res., volume 115, 2010 . J. Semeter, T. W. Butler, M. Zettergren, C. J. Heinselman, and M. J. Nicolls. Composite imaging of auroral forms and convective flows during a substorm cycle. J. Geophys. Res., volume 115, 2010 . M. J. Nicolls, R. H. Varney, S. L. Vadas, P. A. Stamus, C. J. Heinselman, R. B. Cosgrove, and M. C. Kelley. Influence of an inertia-gravity wave on mesospheric dynamics: A case study with the Poker Flat Incoherent Scatter Radar. J. Geophys. Res., volume 115, 2010 . J. J. Sparks, D. Janches, M. J. Nicolls, and C. Heinselman. Determination of physical and radiant meteor properties using PFISR interferometry measurements of head echoes. J Atmos Sol-Terr Phy, volume 72, 2010 . T. W. Butler, J. Semeter, C. J. Heinselman, and M. J. Nicolls. Imaging F region drifts using monostatic phased-array incoherent scatter radar. Radio Sci., volume 45, 2010 . Y. Nishimura, L. R. Lyons, S. Zou, X. Xing, V. Angelopoulos, S. B. Mende, J. W. Bonnell, D. Larson, U. Auster, T. Hori, N. Nishitani, K. Hosokawa, G. Sofko, M. Nicolls, and C. Heinselman. Preonset time sequence of auroral substorms: Coordinated observations by all-sky imagers, satellites, and radars. J. Geophys. Res., volume 115, 2010 . S. Zou, M. B. Moldwin, L. R. Lyons, Y. Nishimura, M. Hirahara, T. Sakanoi, K. Asamura, M. J. Nicolls, Y. Miyashita, S. B. Mende, and C. J. Heinselman. Identification of substorm onset location and preonset sequence using Reimei, THEMIS GBO, PFISR, and Geotail. J. Geophys. Res., volume 115, 2010 . H. Bahcivan, R. Tsunoda, M. J. Nicolls, and C. J. Heinselman. Initial ionospheric observations made by the new Resolute incoherent scatter radar and comparison to solar wind IMF. Geophys. Res. Lett., volume 37, 2010 . S. Zou, L. R. Lyons, M. J. Nicolls, C. J. Heinselman, and S. B. Mende. Nightside ionospheric electrodynamics associated with substorms: PFISR and THEMIS ASI observations. J. Geophys. Res., volume 114, 2009 . S. Zou, L. R. Lyons, M. J. Nicolls, and C. J. Heinselman. PFISR observations of strong azimuthal flow bursts in the ionosphere and their relation to nightside aurora. J. Atmos. Solar-Terr. Phys., volume 71, issue 6, pages 729-737, 2009 . R. H. Varney, M. J. Nicolls, C. J. Heinselman, and M. C. Kelley. Observations of polar mesospheric summer echoes using PFISR during the summer of 2007. J. Atmos. Solar-Terr. Phys., volume 71, issue 3, pages 470-476, 2009 . M. J. Taylor, Y. Zhao, P.-D. Pautet, M. J. Nicolls, R. L. Collins, J. Barker-Tvedtnes, C. D. Burton, B. Thurairajah, J. Reimuller, R. H. Varney, C. J. Heinselman, and K. Mizutani. Coordinated optical and radar image measurements of noctilucent clouds and polar mesospheric summer echoes. J. Atmos. Solar-Terr. Phys., volume 71, issue 6, pages 675-687, 2009 . J. J. Sparks, D. Janches, M. J. Nicolls, and C. J. Heinselman. Seasonal and diurnal variability of the meteor flux at high latitudes observed using PFISR. J. Atmos. Solar-Terr. Phys., volume 71, issue 6, pages 644-652, 2009 . J. J. Sojka, M. J. Nicolls, C. J. Heinselman, and J. D. Kelly. The PFISR IPY observations of ionospheric climate and weather. J. Atmos. Solar-Terr. Phys., volume 71, issue 6, pages 771-785, 2009 . J. J. Sojka, R. L. McPherron, A. P. van Eyken, M. J. Nicolls, C. J. Heinselman, and J. D. Kelly. Observations of ionospheric heating during the passage of solar coronal hole fast streams. Geophys. Res. Lett., volume 36, issue 1, 2009 . J. Semeter, T. Butler, C. Heinselman, M. Nicolls, J. Kelly, and D. Hampton. Volumetric imaging of the auroral ionosphere: Initial results from PFISR. J. Atmos Solar-Terr. Phys., volume 71, issue 6, pages 738-743, 2009 . P. G. Richards, M. J. Nicolls, C. J. Heinselman, J. J. Sojka, J. M. Holt, and R. R. Meier. Measured and modeled ionospheric densities, temperatures, and winds during the international polar year. J. Geophys. Res., volume 114, 2009 . M. J. Nicolls, M. C. Kelley, R. H. Varney, and C. J. Heinselman. Spectral observations of polar mesospheric summer echoes at 33 cm (450 MHz) with the Poker Flat Incoherent Scatter Radar. J. Atmos Solar-Terr. Phys., volume 71, issue 6, pages 662-674, 2009 . R. G. Michell, K. A. Lynch, C. J. Heinselman, and H. C. Stenbaek-Nielsen. High time resolution PFISR and optical observations of naturally enhanced ion acoustic lines. Ann. Geophys., volume 27, issue 4, pages 1457-1467, 2009 . L. R. Lyons, S. Zou, C. J. Heinselman, M. J. Nicolls, and P. C. Anderson. Poker flat radar observations of the magnetosphere-ionosphere coupling electrodynamics of the earthward penetrating plasma sheet following convection enhancements. J. Atmos Solar-Terr. Phys., volume 71, issue 6, pages 717-728, 2009 . L. R. Lyons, H.-J. Kim, X. Xing, S. Zou, D.-Y. Lee, C. Heinselman, M. J. Nicolls, V. Angelopoulos, D. Larson, J. McFadden, A. Runov, and K.-H. Fornacon. Evidence that solar wind fluctuations substantially affect global convection and substorm occurrence. J. Geophys. Res., volume 114, 2009 . M. J. Kosch, B. Gustavsson, C. Heinselman, T. Pedersen, M. T. Rietveld, J. Spaleta, A. Wong, W. Wang, C. Mutiso, B. Bristow, and J. Hughes. First incoherent scatter radar observations of ionospheric heating on the second electron gyro-harmonic. J. Atmos Solar-Terr. Phys., volume 71, issue 1, pages 1959-1966, 2009 . J. D. Kelly and C. J. Heinselman. Initial results from Poker Flat Incoherent Scatter Radar (PFISR). J. Atmos Solar-Terr. Phys., volume 71, issue 6, pages 635, 2009 . S. L. Jones, M. R. Lessard, P. A. Fernandes, D. Lummerzheim, J. L. Semeter, C. J. Heinselman, K. A. Lynch, R. G. Michell, P. M. Kintner, H. C. Stenbaek-Nielsen, and K. Asamura. PFISR and ROPA observations of pulsating aurora. J. Atmos Solar-Terr. Phys., volume 71, issue 6, pages 708-716, 2009 . D. Janches, D. C. Fritts, M. J. Nicolls, and C. J. Heinselman. Observations of D-region structure and atmospheric tides with PFISR during active aurora. J. Atmos Solar-Terr. Phys., volume 71, issue 6, pages 688-696, 2009 . D. L. Hysell, G. Michhue, M. J. Nicolls, C. J. Heinselman, and M. F. Larsen. Assessing auroral electric field variance with coherent and incoherent scatter radar. J. Atmos Solar-Terr. Phys., volume 71, issue 6, pages 697-707, 2009 . J. L. Chau, F. R. Galindo, C. J. Heinselman, and M. J. Nicolls. Meteor-head echo observations using an antenna compression approach with the 450 MHz Poker Flat Incoherent Scatter Radar. J. Atmos Solar-Terr. Phys., volume 71, issue 6, pages 636-643, 2009 . J. D. Mathews, S. J. Briczinski, D. D. Meisel, and C. J. Heinselman. Radio and Meteor Science Outcomes From Comparisons of Meteor Radar Observations at AMISR Poker Flat, Sondrestrom, and Arecibo. Earth Moon Planet, volume 102, pages 365-372, 2008 . R. G. Michell, K. A. Lynch, C. J. Heinselman, and H. C. Stenbaek-Nielsen. PFISR nightside observations of naturally enhanced ion acoustic lines, and their relation to boundary auroral features. Ann. Geophys., volume 26, issue 1, pages 3623-3639, 2008 . D. L. Hysell, G. Michhue, M. F. Larsen, R. Pfaff, M. Nicolls, C. Heinselman, and H. Bahcivan. Imaging radar observations of Farley Buneman waves during the JOULE II experiment. Ann. Geophys., volume 26, issue 7, pages 1837-1850, 2008 . C. J. Heinselman and M. J. Nicolls. A Bayesian approach to electric field and E-region neutral wind estimation with the Poker Flat Advanced Modular Incoherent Scatter Radar. Radio Sci., volume 43, issue 5, 2008 . B. Gustavsson, M. Kosch, A. Wong, T. Pedersen, C. Heinselman, C. Mutiso, B. Bristow, J. Hughes, and W. Wang. First estimates of volume distribution of HF-pump enhanced emissions at 6300 and 5577 Å: a comparison between observations and theory. Ann. Geophys., volume 26, issue 1, pages 3999-4012, 2008 . M. J. Nicolls and C. J. Heinselman. Three-dimensional measurements of traveling ionospheric disturbances with the Poker Flat Incoherent Scatter Radar. Geophys. Res. Lett., volume 34, issue 2, 2007 . M. J. Nicolls, C. J. Heinselman, E. A. Hope, S. Ranjan, M. C. Kelley, and J. D. Kelly. Imaging of Polar Mesosphere Summer Echoes with the 450 MHz Poker Flat Advanced Modular Incoherent Scatter Radar. Geophys. Res. Lett., volume 34, issue 2, 2007 . D. L. Hysell, J. Drexler, E. B. Shume, J. L. Chau, D. E. Scipion, M. Vlasov, R. Cuevas, and C. Heinselman. Combined radar observations of equatorial electrojet irregularities at Jicamarca. Ann. Geophys., volume 25, issue 2, pages 457-473, 2007 . S. Oyama, B. J. Watkins, F. T. Djuth, M. J. Kosch, P. A. Bernhardt, and C. J. Heinselman. Persistent enhancement of the HF pump-induced plasma line measured with a UHF diagnostic radar at HAARP. J. Geophys. Res., volume 111, 2006 .