The Stanford University ELF/VLF Radiometer Project: Measurement of the Global Distribution of ELF/VLF Electromagnetic Noise

S tanford University is currently conducting a global survey of electromagnetic noise in the 10 32,000 Hz (ELF/V LF) frequency band using a network of eight computer-controlled receiving systems, or ‘radiom eters.’ One goal of this m easurem ent program is to improve communication in the E L F/V L F band by providing more upto-date and complete inform ation about the properties of E L F/V L F noise (both na tu ra l and man-made) than is currently available—the last extensive survey of noise in the same frequency band was made over two decades ago. In this p resentation we describe the Stanford E L F /V L F noise m easurem ent project, including the instrum enta tion comprising each of the radiometers, the form of the ir analog and digital m easurem ents (which are made under the control of a minicomputer), and the d a ta processing techniques th a t will be used. T he results of previous noise surveys are briefly reviewed and the significance of the overall decline of noise power with increasing frequency revealed by these surveys and other studies is discussed in the context of the scientific applications of the noise d a ta obtained by the radiom eter network.