VHF Radar Images of Artificial Field‐Aligned Ionospheric Irregularities in the Subauroral E Region

Artificial E region field-aligned plasma density irregularities (AFAIs) have been generated using the High-frequency Active Auroral Research Program (HAARP) ionospheric modification facility in Gakona and observed with a 30 MHz coherent scatter radar imager in Homer, Alaska. The AFAIs were generated using a distinctive, twisted-beam antenna pattern that illuminated a particularly broad volume over...