Correlation Between Measured Man-Made Noise Levels and the Density of Habitation

Abstract

The results of the man-made noise measurement campaign, organized by the Dutch society of radio amateurs, VERON, are compared with geographical data like the number of residential livings inside a circular area around the measurement location limited by a chosen distance. For each frequency band, correlation factors are derived as a function of the distance. It is shown that a strong correlation exists between the measured man-made noise floor and the density of habitation. This result proves that in this campaign, measured noise floor levels are mainly the result of accumulation of noise power from a large number of small sources spread in the houses, instead of being caused by a single, or a few, strong sources. The correlation is maximal at distances up to 200-300 m from the measurement location. Beyond that range, the correlation decreases, indicating that mainly sources in a range up to 300 m are relevant in determining the noise floor. This conclusion is supported by the observation that the slope of regression lines increasingly deviates from a theoretically derived slope at ranges over 300 m.

Model of Cumulation of Man-Made Radio Noise, Applied to Sources of Emissions Limited by EMC Standards, and Compared With Noise Measurements

“…6, for K = −0.5 dB, we learn that the range r max (K), wherein the radiated power from each source participate in the total noise FS at location M, is very limited and depending on frequency and on the exclusion distance r min . The value of this distance appears to be in the same order of magnitude, as we concluded in [12], namely up to 300 m, frequency depending.…”

“…The maximum range according the cumulation model, wherein the contribution of MMN source is relevant to the accumulated field strength level, is equal to what is found by correlation between measured field strength levels and the local density of habitation in [12], and reaches up to about 300 m, depending on frequency.…”

“…We combine r i • lexcess,i (r i , f) ≡ li (r i , f). Values for l(r, f ) are derived in [12]. So for the field strength, we can write…”

“…The study, in this article, is not directed on wire-line broadband telecommunication systems, but is focussed on MMN sources in ordinary house-hold environments, e.g., on situations wherein appliances inject electrical disturbance into mains networks. In the preparation of this article, we investigated the MMN floor in [2], the correlation between the MMN floor levels and the density of habitation [12], and the propagation in residential areas [13]. For illustrative purpose we show Photo 1, related to the noise measurements, and Photo 2 showing the beacon transmitter as used in the propagation measurements.…”

Propagation Measurements and Analysis on MF and HF Bands in Urban Areas in The Netherlands

“…MMN in the frequency range of 0.47 to 50 MHz was investigated earlier [1]. A further statistical study of the measurement results revealed that there is a strong correlation between the measured noise floor and the density of habitation [2]. These results raise the question of how does the radio noise propagate in these populated areas, and what is the propagation loss with distance.…”