Accession Number : ADA514755


Title :   ELF Waves Generated by Modulated HF Heating of the Auroral Electrojet and Observed at a Ground Distance of Approximately 4400 km


Descriptive Note : Journal article


Corporate Author : STANFORD UNIV CA DEPT OF ELECTRICAL ENGINEERING


Personal Author(s) : Moore, R C ; Inan, U S ; Bell, T F ; Kennedy, E J


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a514755.pdf


Report Date : 22 May 2007


Pagination or Media Count : 8


Abstract : We present calibrated measurements of ELF waves generated by modulated HF heating of the auroral electrojet by the High frequency Active Auroral Research Program (HAARP) HF transmitter in Gakona, Alaska, and detected after propagating more than 4400 km in the Earth-ionosphere waveguide to Midway Atoll. The magnitude of the 2125 Hz wave received at Midway Atoll is consistent with the radiation from a horizontal dipole located at the altitude of the maximum Hall conductivity variation (created by modulated HF heating) and radiating approximately 4-32 W. The HF-ELF conversion efficiency at HAARP is thus estimated to be approximately 0.0004-0.0032% for the 2125 Hz wave generated using sinusoidal amplitude modulation.


Descriptors :   *ELECTROJETS , *EXTREMELY LOW FREQUENCY , *WAVE PROPAGATION , *LONG RANGE(DISTANCE) , ELECTRON DENSITY , HALL EFFECT , SIGNAL TO NOISE RATIO , NUMERICAL ANALYSIS , EFFICIENCY , WAVEGUIDES , ELECTROMAGNETIC RADIATION , HEATING , HIGH ALTITUDE , ATTENUATION , MODULATION , SIGNAL GENERATION , HIGH FREQUENCY , POLARIZATION , REPRINTS , CONVERSION , IONOSPHERE


Subject Categories : Radiofrequency Wave Propagation


Distribution Statement : APPROVED FOR PUBLIC RELEASE