Alaska to New Zealand whistler-mode transmission at 6.8 kHz

Abstract : The vlf signals that were transmitted by The Aerospace Corporation group at Port Heiden, Alaska, were received by the University of Otago group in Dunedin, New Zealand, in August 1972. The transmitter, using a balloon-supported antenna, was operated at 6.8 kHz with a radiated power of 13W. The signal intensity at Dunedin was 35 uV/m, and the signal delay was determined to be 1.13 plus or minus 0.01 sec. The delay and the existence of natural whistlers indicated there was a high probability that the signals traveled in a duct at L = 2.92 plus or minus 0.04. Estimates of the expected signal strength at Dunedin indicated that a 'natural' amplification of the order of 30 dB was probably secured in the duct. (Author)