Man-Made Noise Power Measurements at VHF and UHF Frequencies

摘要

Man-made noise generated by automotive ignition, power distribution andtransmission, industrial equipment, consumer products, and lighting systems degrades the performance of radio systems. Man-made noise models, derived from measurements made in the 1970s, may be inaccurate due to changes in these technologies. For example, recent man-made noise measurements performed by ITS in the 136 to 138 MHz meteorological satellite band indicated that man-made noise power in residential areas is lower than predictions by these models. However, these same measurements indicated that man-made noise in business areas has not changed. UHF man-made noise has not been comprehensively measured and modeled. This report describes UHF man-made noise measurements conducted in the Denver, CO metropolitan area in 1999. Measurement data is analyzed and results are compared to other measurements and models. These results showed that 402.5 MHz UHF noise levels in business areas were high enough to adversely affect communication system performance some of the time.