In order to modernize the U.S. power grid, with efforts to create a Smart Grid network, thousands of devices called phasor measurement units (PMUs) have been deployed across the U.S. continent to continuously monitor the power grid state in real-time. Each PMU measures voltage and current phasors at its local substation, and relies on GPS to precisely time-tag these measurements. However, because civilian GPS signals are unencrypted with a publicly available signal structure, these signals are vulnerable to being spoofed, potentially resulting in false timing solutions and large-scale power disruptions. 

While the civilian signal is vulnerable to spoofing, the simultaneously broadcast military GPS signals are encrypted and, thus, cannot be forged by an attacker. Thus, using the power grid's secure communication channels, we compare the received military GPS signal against that of other receivers in the power grid network, in order to validate the consistency of the received military signature and ensure authentic GPS-based timing at each station.

Related Publications:

• T. Mina, S. Bhamidipati, and G. Gao, “GPS spoofing detection for the power grid network using a multireceiver hierarchical framework architecture,” NAVIGATION, Journal of the Institute of Navigation, vol. 66, no. 4, 2019. [paper]

• T. Mina, S. Bhamidipati, and G. Gao, “Detecting GPS spoofing via a multi-receiver hybrid communication network for power grid timing verification,” in Institute of Navigation (ION) GNSS+ Conference, Miami, FL, Sep. 2018, pp. 2963–2977. [paper]

• S. Bhamidipati, T. Mina, and G. Gao, “GPS time authentication against spoofing via a network of receivers for power systems,” in IEEE/ION Position, Location and Navigation Symposium (PLANS) Conference, Monterey, CA, Sep. 2018, pp. 1485–1491. [paper]