Some ionosonde observations of ionosphere modification by very high power, high frequency ground-based transmission

Abstract

Some early observations of significant ionospheric modification resulting from F-region heating by a very high power, high frequency transmitter located near Boulder, Colorado, are presented in this paper. A description of the Platteville heating transmitter facility, the locations of ionosonde and photometric diagnostic equipments, and the geometry of the experiment are given in a companion paper by Utlaut [1970]. A single-plane inverted log periodic antenna, which has a half-power beam-width of the order of 90°, was used for transmitting. The ionosonde transmitter, which has a peak power of about 25 kw, was operated by using a 200-Hz pulse repetition rate with a pulse duration of 64 μsec.