Publication Date:
2019
Description:
Abstract
Modern measurement campaigns of man‐made radiofrequency (RF) noise have reported results from fixed locations which are assumed to be representative of the surroundings. Models derived from these measurements include parameters to express the variability in time and in space over very large distances (i.e. differences between cities). Despite the rapidly evolving mixture of noise sources, especially in modern urban environments, spatial variation of RF noise power at the scale of streets and blocks is essentially unknown in the VHF and UHF bands.
Using a portable calibrated noise measurement system of our design, RF noise was recorded over a 1 MHz bandwidth for frequencies of 142.0, 246.5 and 972 MHz. Noise surveys were conducted during daytime working hours in several different neighborhoods within Boston, Massachusetts, USA, with each survey transiting a fixed, several kilometer long route, repeated twice to enable separation of temporal from spatial variability.
Significant and spatially repeatable variations in median power, peak power, and voltage deviation were observed over distances of tens to hundreds of meters, dependent upon the measurement frequency. The observed spatial patterns of median and peak power appear to be repeatable on time scales of hours to weeks, and likely beyond, suggesting that these noise patterns are persistent features of the urban environment.
Print ISSN:
0048-6604
Electronic ISSN:
1944-799X
Topics:
Geosciences
,
Physics
