A novel method for the evaluation of polarization and hemisphere coverage of HF radio noise measurement antennas

In HF (3–30 MHz) communications the ambient electromagnetic background noise or ‘radio noise’ generally is the limiting factor in reception. Radio noise measurements are needed for spectrum pollution control and to provide reference levels for radio system design. This article discusses the influence of the measurement antenna on the measurement results. A novel method to compare the polarization and hemisphere coverage of radio noise measurement antennas is proposed. This method is used to compare three HF radio noise measurement antennas. A novel omni-directional antenna is introduced which has improved sensitivity for high angle skywave signals and which is impartial to the polarization of the incoming wave.