Measurement and analysis of man-made noise in VHF and UHF bands

Abstract

The Institute for Telecommunication Sciences measured man-made noise in portions of the VHF and UHF bands. This paper provides an overview of the measurement and analysis methods used and examples of the results. The VHF measurements were made as part of a link analysis for the broadcast of digital satellite weather images at 137 MHz. The motivation for these measurements was that published man-made noise statistics are probably outdated because they are based on noise measurements made over two decades ago. Since that time, technological advances have changed man-made noise emissions. For example, automotive emissions have been reduced, while emissions from other sources such as unregulated electronic devices (e.g., computers and microwave ovens) and other electrical equipment such as electric motors have probably increased significantly. In addition to the VHF measurement results, we present an example of measured noise statistics at 2460 MHz. At this frequency, the dominant noise sources are thought to be microwave ovens. The data we obtained show that there are significant changes in the character of man-made noise which should be considered in the design and implementation of radio systems. Also, additional measurements are necessary to characterize adequately VHF and UHF man-made noise in high technology environments such as modern urban and suburban areas.