"DETECTION AND ANALYSIS OF PLASMA BUBBLES AT 20 MHz RADIO
FREQUENCY"
by Professors John C. Mannone and Wanda Diaz
Society of Amateur Radio Astronomers 2004 Conference
Tuesday June 29, 2004
National Radio Astronomy Observatory
Green Bank, WV
ABSTRACT:
Charge deficient holes in the F-region, called plasma bubbles, are typically
detected above the equatorial zone. Some of the traditional techniques of detection involve sensitive receivers
called riometers tuned to 30 MHz to record time variations or rocket-borne Langmuir probes
measure the fluctuation of electron number density. In this work, the electron number density variations are recorded indirectly.
Astrophysical radio waves are modulated by these variations as they travel through the ionosphere. Spectral analysis
of decametric radio signals acquired with 20 MHz antennas will provide similar information about the ionosphere. The
behavior of the radio noise floor will show if radio light is scintillated. This technique is applied to data from
Puerto Rico. Though just north of the magnetic equatorial zone, power spectra disclose radio twinkling by the sudden
post-sunset onset of plasma bubbles just before local midnight. ***********************************************************************
