A diagnostic system for the study of extremely long wavelength emission produced by ionospheric modification


  • M. R. Baker,

  • T. W. Collins,

  • H. S. Lee,

  • A. J. Ferraro


This paper describes a diagnostic system developed for the study of radio signals at frequencies below 8 kHz. Of specific interest are emissions produced by high-frequency heating of the ionosphere which modulates natural ionospheric current systems. Dual receivers allow independent reception on orthogonal loop antennas, and microcomputer systems provide real-time data acquisition and processing of all experimental data. Provisions are also made for automatic control of modulating frequency applied to the heating transmitters; operating frequencies may be changed on a preset schedule in tandem with receiver tuning.