Geomagnetic storms drive geomagnetically induced currents (GICs) in high-voltage power transmission systems. GICs thus carry information about the near-space environment conditions. The U.S. high-voltage power transmission system was used as an extremely large antenna to extract unprecedented spatiotemporal space physical and geological information from distributed GIC observations.

GICs are measured using a differential magnetometer technique involving one fluxgate magnetometer under a transmission line, and another reference magnetometer station nearby. GICs carry information about near-space phenomena, which is of interest to NASA science. GICs can be harmful to the power grid, so the information is valuable to transmission system operators.

A reference station allows subtraction of the natural field from the line measurement, leaving only the GIC-related Biot-Savart field, allowing inversion of the GIC amplitude. The magnetometer stations are designed to be autonomous and low cost, allowing large-scale application with many measurement locations.

This work was done by Antti Pulkkinen and Todd Bonalsky of Goddard Space Flight Center. NASA is seeking partners to further develop this technology through joint cooperative research and development. For more information about this technology and to explore opportunities, please contact Scott Leonardi at This email address is being protected from spambots. You need JavaScript enabled to view it.. GSC-17256-1

NASA Tech Briefs Magazine

This article first appeared in the September, 2016 issue of NASA Tech Briefs Magazine.

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