The Bruny Island radio spectrometer

A radio spectrometer has been built on Bruny Island, south of Hobart, for the study of solar bursts in the rarely observed frequency range from 3 to 20 MHz. This spectrometer is an adaptive device that employs digital techniques to avoid most of the strong terrestrial interference prevalent in this frequency range. The residual interference that cannot be avoided is excised during off-line processing. As a result, successful observations are made down to the minimum frequency that can propagate through the ionosphere to the antenna. This minimum frequency depends upon the zenith distance of the Sun and it is usually between 4 and 8 MHz.