Conjugate magnetospheric transmissions at VLF from Alaska to New Zealand

Abstract

A very low frequency (VLF) magnetospheric transmission experiment was conducted between Port Heiden, Alaska, and Dunedin, New Zealand, during August 1972. The transmitter was located at Port Heiden (56.93øN, 201.42øE), and the receiver was located at Dunedin (45.87øS, 170.22øE).A mobile VLF transmitter developed by the U.S. Navy for shore-to-submarine communication was used for the experiment in Port Heiden. The unique feature of this transmitter is the antenna, which is a conducting cable suspended by a helium-filled balloon. The original system was designed to operate with the balloon at altitudes up to 3000 m. The size of the balloon used in this experiment was limited by available resources, and the maximum altitudes possible were between 1200 and 1500 m. Vertical radiators of these dimensions are required because at 10 kHz, the wavelength is approximately 30 km so that antennas of sensible dimensions are much shorter than a wavelength and hence are poor radiators. Conjugate VLF transmissions have been conducted or are

A new type of VLF emission triggered at low altitude in the subauroral region by Siple Station VLF transmitter signals

“…The main goal of these, and similar, experiments is to acquire understanding of interactions between coherent VLF waves and energetic particles in the magnetosphere and ionosphere [Helliwell and Katsufrakis, 1974;McPherson et al, 1974.;Dowden et al, 1978;Bell et al, 1981a;Bell et al, 1983]. Sources of the coherent waves involved in these studies include VLF transmitters, large-scale power grids, whistlers, and other natural coherent VLF signals.…”