Radio noise from towns: measured from an airplane

Science. 1973 Aug 10;181(4099):543-5. doi: 10.1126/science.181.4099.543.

Abstract

Measurements of broadband radio noise in the range 73 to 440 megahertz were made over several small Illinois cities during August, September, and December 1972. Results for cities with a population larger than 25,000 are presented as brightness temperatures between 2400 and 9600 degrees Kelvin. Even the smallest villages produce significant noise pollution. There is considerable diurnal variation and some evidence for seasonal variation.