Man-Made Radio Noise Levels at 150 kHz to 32 MHz Near a Large Antarctic Base

Over recent years increased effort has been applied to scientific research in the Antarctic. This growth has resulted in increased scientific and logistics activity at McMurdo Station, the principal U.S. base. As a consequence contamination of the natural environment has become a problem. A particular example of this contamination is interference to communications receivers and sensitive scientific measuring equipment by radio noise. In November 1970 a survey of radio noise levels near McMurdo was conducted to evaluate the possibility of establishing a low-noise experimental station for the operation of sensitive experiments. The instrument used in the survey, a Stoddart NM-25T, was not sensitive enough to measure the atmospheric noise levels at extremely quiet sites, but was suitable for determining the man-made levels near the base. In central McMurdo the man-made levels, which are mainly attributable to power line noise, are about 45 dB greater than the atmospheric levels expected for the area. Furthermore, they are about 60 dB greater than the man-made levels recorded near another Antarctic base. For the McMurdo area to continue to be used for the operation of sensitive equipment some control must be imposed on the installation and operation of equipment that generates noise.