Gao student wins Best Paper Award for GPS research at ION GNSS+ 2015

10/28/2015 David Robertson, Coordinated Science Lab

Assistant Prof. Grace Gao and her student develop robust tracking of power grid conditions.

Written by David Robertson, Coordinated Science Lab

From left: Akshay Shetty, Yuting Ng, Derek Chen, Grace Xingxin Gao
From left: Akshay Shetty, Yuting Ng, Derek Chen, Grace Xingxin Gao
From left: Akshay Shetty, Yuting Ng, Derek Chen, Grace Xingxin Gao
Last month, CSL grad student Yuting Ng received the award for Best Paper of the Session at the 27th International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS+ 2015). Yuting’s paper, written in collaboration with Grace Xingxin Gao, assistant professor of aerospace engineering and CSL at Illinois, is titled “Advanced Multi-Receiver Position-Information-Aided Vector Tracking for Robust GPS Time Transfer to PMUs.”

In her paper, Yuting discusses a new, robust system for synchronizing Phasor Measurement Units (PMUs), which are used to measure conditions of the power grid and provide assistance with real-time operations and off-line analysis to improve reliability and efficiency. PMU readings are synchronized using GPS, which -- in addition to its better-known positioning capabilities -- keeps time at the nanosecond level.

Unfortunately, the GPS signal is weak and vulnerable to jamming (overwhelming the signal with noise) and spoofing (broadcasting a false signal with a fake position or time). There is concern that attacks on the GPS signal could lead to incorrect measurements from the PMUs, resulting in power outages.

“If this attack happens on the power grid level, it could cause widespread outages,” Yuting says. “People don’t want to have this risk within the power grid so they are not integrating PMUs as control mechanisms yet. That is why we’re working to make the GPS signal robust so that we can mitigate attacks.”

The U.S. grid operates according to a sinusoidal waveform with peaks and valleys, at a frequency of 60 cycles per second. In order to control the grid, power companies need a snapshot of many different points, which are gathered by taking measurements of voltages and currents. At present, the old technology produces very infrequent measurements. PMUs would provide these updated, precisely-synchronized measurements.

With equipment sponsored by the Trustworthy Cyber Infrastructure for the Power Grid (TCIPG), Yuting and colleagues are able to collect real signals. They then use software, written by Yuting, to monitor the signals and test the new system. Though the TCIPG project recently ended, the team is funded by a new grant, the Cyber Resilient Energy Delivery Consortium (CREDC): “We will continue working on how to make the system more secure and robust,” said Gao.

This Best Paper Award is not the first time Yuting has proven herself to be a formidable force in engineering. She was recognized on the Bronze Tablet of her undergraduate class at Illinois, having landed in the top three percent of students with an exceptional GPA. When asked what keeps her motivated in the midst of this challenging research, she noted a phrase that Prof. Gao shared with her, “Take action, and you will feel powerful.”


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This story was published October 28, 2015.