Grace Xingxin Gao

Research | Honors and Awards | Publications | Talks | CV

Grace Xingxin Gao Durand 453 496 Lomita Mall Stanford CA 94305 gracegao(at)stanford(dot)edu

I am a Research Associate in the Global Positioning System (GPS) Lab at Stanford University. I completed the Ph.D. degree in electrical engineering at Stanford in 2008, supervised by Professor Per Enge. My dissertation is titled Towards Navigation based on 120 Satellites - Analyzing the New Signals.

I received the B.S. degree in mechanical engineering and the M.S. degree in electrical engineering from Tsinghua University in China in 2001 and 2003, respectively.

Current Research

Collaborative localization and tracking of GNSS jammers

Investigating the impact of Personal Privacy Devices (PPDs) using live data collected at the Wide Area Augmentation System (WAAS) reference stations. Using multiple networked GPS receivers to collaboratively localize the jammers.

Arctic Navigation

Investigating the Arctic extension of space-based augmentation systems addressing special challenges of high latitudes, such as lack of reference stations, weak communication linkage, and degraded vertical accuracy due to lack of high elevation GNSS satellites.

Characterizing GPS Signal-in-space Errors

Developing top-down and bottom-up algorithms to characterize GPS signal-in-space errors. Data mining GPS ephemeris data of the past decade based on a global receiver network of over 300 receivers.

Past Research

GNSS Monitoring Facility

Building system to monitor Global Navigation Satellite Systems in real-time to detect power failure, changes in signal transmission, ionosphere scintillation, etc.

Multi-Constellation Analysis

Analyzing interoperability of multiple GNSS constellations. Evaluating the overall performance of the multi-constellation system and the potential interference among the constellations.

Pulsed Interference Analysis and Mitigation

Analyzed Distance Measuring Equipment (DME) and Tactical Air Navigation (TACAN) interference environments and their degradation of Global Positioning System (GPS) L5 and Galileo E5a/E5b signals. Investigated techniques for pulsed interference mitigation to improve coexistence of GPS/Galileo with DME/TACAN systems.

Compass-M1 Code Analysis

Reverse-engineered pseudorandom noise (PRN) codes in all frequency bands (E2, E5b & E6) of the first Chinese global navigation satellite Compass-M1. Proved that all Compass-M1 codes are Gold codes and derived their code generators as linear shift feedback registers. Applied PRN codes in software receiver to acquire and track Compass-M1 satellite.

Galileo GIOVE-A Code Analysis

Reverse-engineered pseudorandom noise (PRN) code generators of the first European global navigation satellite GIOVE-A. Studied pseudorandomness and correlation properties of PRN codes to evaluate their processing gain and tolerance to noise and interference.

Honors and Awards

Best Presentation of the Session Award, Institute of Navigation (ION) Global Navigation Satellite Systems (GNSS) Conference (2011)

Best Presentation of the Session Award, ION Global Navigation Satellite Systems Conference (2010)

William E. Jackson Award, Radio Technical Commission for Aeronautics (RTCA) (2009)

50 GNSS Leaders to Watch, GPS World Magazine (2009)

Early Achievement Award, Institute of Navigation (2008)

Award for Outstanding Self-Financed Chinese Students Abroad, Government of China (2008)

Best Presentation of the Session Award, ION Global Navigation Satellite Systems Conference (2007)

Student Paper Award, ION Global Navigation Satellite Systems Conference (2007)

Excellent Master's Thesis Award, Tsinghua University (2003)

Graduate Student Comprehensive Scholarship, Tsinghua University (2002)

Exceptional Graduate of Beijing, Beijing Government (2001)

Exceptional Graduate of Tsinghua University, Tsinghua University (2001)

Excellent Undergraduate Thesis Award, Tsinghua University (2001)

Tsinghua Exceptional Student Scholarship, Tsinghua University (1998-2000)

Publications

Journal and Magazine Articles

Grace Xingxin Gao, Holmer Denks, Achim Steingassnd, Michael Meurer, Todd Walter, and Per Enge, DME Interference Mitigation Based on Flight Test Data Over European Hot Spot, GPS Solutions, Accepted.

Grace Xingxin Gao and Per Enge, How Many GNSS Satellites Are Too Many? IEEE Transactions on Aerospace and Electronic Systems, Accepted.

Liang Heng, Grace Xingxin Gao, Todd Walter, and Per Enge, GPS Signal-in-Space Performance Evolution: Data Mining 400 Million Navigation Messages of the Last Decade from a Global Network of 360 receivers, IEEE Transactions on Aerospace and Electronic Systems, Accepted.

Sam Pullen and Grace Xingxin Gao, GNSS Jamming in the Name of Privacy: Potential Threat to GPS Aviation, Inside GNSS Magazine, March-April 2012. [pdf]

Grace Xingxin Gao, Liang Heng, Todd Walter, and Per Enge, Breaking the Ice: Navigation in the Arctic, Inside GNSS Magazine, September-October 2011. [pdf]

R. Eric Phelts, Grace Xingxin Gao, Gabriel Wong, Liang Heng, Todd Walter, Per Enge, Stefan Erker, Steffen Thoelert, and Michael Meurer, Aviation Grade, New GPS Signals Chips Off the Block IIF, Inside GNSS Magazine, July-August 2010. [pdf]

Steffen Thoelert, Steffen Erker, Michael Meurer, Liang Heng, Eric Phelts, Grace Xingxin Gao, Gabriel Wong, Todd Walter, and Per Enge, On the Air, New Signals from the First GPS IIF Satellite, Inside GNSS Magazine, July-August 2010. Cover Story. [pdf]

Patrick Henkel, Grace Xingxin Gao, Todd Walter and Christoph Gunther, Robust Multi-Carrier, Multi-Satellite Vector Phase Locked Loop with Wideband Ionospheric Correction and Integrated Weighted RAIM, Journal of Italian Institute of Navigation, issue 190, December 2009. [pdf]

Grace Xingxin Gao, Liang Heng, David De Lorenzo, Sherman Lo, Dennis Akos, Alan Chen, Todd Walter, Per Enge and Bradford Parkinson, Modernization Milestone: Observing the First GPS Satellite with an L5 Payload, Inside GNSS Magazine, May-June 2009. [pdf]

Grace Xingxin Gao, Alan Chen, Sherman Lo, David De Lorenzo and Per Enge, Compass-M1 Broadcast Codes in E2, E5b and E6 Frequency Bands, IEEE Journal of Selected Topics in Signal Processing, Special Issue on Advanced Signal Processing for GNSS and Robust Navigation, August 2009. [pdf]

Grace Xingxin Gao, Dennis Akos, Todd Walter and Per Enge, GIOVE-B on the Air: Understanding Galileo's New Signals, Inside GNSS Magazine, May-June 2008. [pdf]

Grace Xingxin Gao, Alan Chen, Sherman Lo, David De Lorenzo and Per Enge, GNSS over China: the Compass MEO Satellite Codes, Inside GNSS Magazine, July-August 2007. Cover Story. [pdf]

Sherman Lo, Alan Chen, Per Enge, Grace Xingxin Gao, Dennis Akos, Jean-Luc Issler, Lionel Ries, Thomas Grelier and Joel Dantepal, GNSS Album: Images and Spectral Signatures of the New GNSS Signals, Inside GNSS Magazine, May-June 2006. Cover Story. [pdf]

Zhe Xiang, Song Song, Jin Chen, Hao Wang, Jian Huang and Grace Xingxin Gao, A Wireless LAN-based Indoor Positioning Technology, IBM Journal of Research and Development, vol. 48, no. 5, September-November 2004. [pdf]

Conference Papers

Sam Pullen, Grace Xingxin Gao, Carmen Tedeschi, and John Warburton, The Impact of Uninformed RF Interference on GBAS and Potential Mitigations, ION International Technical Meeting 2012, Newport Beach, California, January 2012. [pdf]

Liang Heng, Grace Xingxin Gao, Todd Walter, and Per Enge, Statistical Characterization of GLONASS Broadcast Clock Errors and Signal-In-Space Errors, ION International Technical Meeting 2012, Newport Beach, California, January 2012. [pdf]

Grace Xingxin Gao, Liang Heng, Todd Walter, and Per Enge, Breaking the Ice: Navigating in the Arctic, ION Global Navigation Satellite Systems Conference 2011, Portland, Oregon, September 2011. Best Presentation of the Session Award. [pdf]

Liang Heng, Grace Xingxin Gao, Todd Walter, and Per Enge, Statistical Characterization of GLONASS Signal-In-Space Errors, ION Global Navigation Satellite Systems Conference 2011, Portland, Oregon, September 2011. [pdf]

Myungjun Choi, Juan Blanch, Dennis Akos, Liang Heng, Grace Xingxin Gao, Todd Walter, and Per Enge, Demonstrations of Multi-Constellation Advanced RAIM for Vertical Guidance using GPS and GLONASS Signals, ION Global Navigation Satellite Systems Conference 2011, Portland, Oregon, September 2011. [pdf]

Stefan Erker, Steffen Thoelert, Johann Furthner, Michael Meurer, Grace Xingxin Gao, Liang Heng, Todd Walter, and Per Enge, GLONASS K First in Orbit Signal in Space Analysis of Russian New Satellite Generation, ION Global Navigation Satellite Systems Conference 2011, Portland, Oregon, September 2011. [pdf]

Grace Xingxin Gao, Liang Heng, Gabriel Wong, Eric Phelts, Juan Blanch, Todd Walter, Per Enge, Stefan Erker, Steffen Thoelert, and Michael Meurer, GPS in Mid-life with an International Team of Doctors, Analyzing IIF-1 Satellite Performance and Backward- Compatibility, ION Global Navigation Satellite Systems Conference 2010, Portland, Oregon, September 2010. Best Presentation Award. [pdf]

Liang Heng, Grace Xingxin Gao, Todd Walter, and Per Enge, Statistical Characterization of GPS Signal-In-Space Errors, ION International Technical Meeting 2011, San Diego, California, January 2011.[pdf]

Patryk Jurkowski, Patrick Henkel, Grace Xingxin Gao, and Christoph Gunther, Integer ambiguity resolution with tight and soft baseline constraints for freight stabilization at helicopters and cranes, ION National Technical Meeting 2011, San Diego, California, January 2011.[pdf]

David Varodayan and Grace Xingxin Gao, Redundant Metering for Integrity with Information-Theoretic Confidentiality, Proc. IEEE International Conference on Smart Grid Communications, SGC 2010, Gaithersburg, Maryland, October 2010. [pdf]

Grace Xingxin Gao, Liang Heng, Gabriel Wong, Eric Phelts, Juan Blanch, Todd Walter, Per Enge, Stefan Erker, Steffen Thoelert, and Michael Meurer, GPS in Mid-life with an International Team of Doctors, Analyzing IIF-1 Satellite Performance and Backward- Compatibility, ION Global Navigation Satellite Systems Conference 2010, Portland, Oregon, September 2010. Best Presentation of the Session Award. [pdf]

Liang Heng, Grace Xingxin Gao, Todd Walter, and Per Enge, GPS Signal-in-Space Anomalies in the Last Decade, Data Mining of 400,000,000 GPS Navigation Message, ION Global Navigation Satellite Systems Conference 2010, Portland, Oregon, September 2010. [pdf]

Grace Xingxin Gao, Haochen Tang, Juan Blanch, Jiyun Lee, Todd Walter, and Per Enge, Methodology and Case Studies of Signal-in-Space Error Calculation Top-down Meets Bottom-up, ION Global Navigation Satellite Systems Conference 2009, Savannah, Georgia, September 2009. [pdf]

Patrick Henkel, Grace Xingxin Gao, Todd Walter, and Christoph Gunther, Robust Multi-Carrier, Multi-Satellite Vector Phase Locked Loop with Wideband Ionospheric Correction and Integrated Weighted RAIM, ENC Global Navigation Satellite Systems Conference 2009, Naples, Italy, May 2009. [pdf]

Grace Xingxin Gao, Dennis Akos, Todd Walter, and Per Enge, Understanding the GIOVE-B Broadcast Codes of the Galileo System, IEEE Asilomar Conference on Signals, Systems and Computers, Pacific Grove, California, October 2008. Invited Paper. [pdf]

Shankar Ramakrishnan, Grace Xingxin Gao, David De Lorenzo, Todd Walter, Per Enge, and Dennis Akos, Design and Analysis of Reconfigurable Embeded GNSS Receivers Using Model-Based Design Tools, ION Global Navigation Satellite Systems Conference 2008, Savannah, Georgia, September 2008. Best Presentation Award. [pdf]

Grace Xingxin Gao, Alan Chen, Sherman Lo, David De Lorenzo, and Per Enge, Compass-M1 Broadcast Codes and their Application to Acquisition and Tracking, ION National Technical Meeting 2008, San Diego, California, January 2008. [pdf]

Grace Xingxin Gao, DME/TACAN Interference and its Mitigation in L5/E5 Bands, ION Global Navigation Satellite Systems Conference 2007, Fort Worth, Texas, September 2007. Best Presentation Award and Student Paper Award. [pdf]

Grace Xingxin Gao, David De Lorenzo, Todd Walter, and Per Enge, Acquisition and Tracking of GIOVE-A Broadcast L1/E5/E6 Signals and Analysis of DME/TACAN Interference on Receiver Design, ENC Global Navigation Satellite Systems Conference 2007, Geneva, Switzerland, May 2007. [pdf]

Grace Xingxin Gao, Seebany Datta-Barua, Todd Walter, and Per Enge, Ionosphere Effects for Wideband GNSS Signals, ION Annual Meeting 2007, Cambridge, Massachusetts, April 2007. [pdf]

Grace Xingxin Gao, David De Lorenzo, Alan Chen, Sherman Lo, Dennis Akos, Todd Walter, and Per Enge, Galileo GIOVE-A Broadcast E5 Codes and their Application to Acquisition and Tracking, ION National Technical Meeting 2007, San Diego, California, January 2007. [pdf]

Grace Xingxin Gao, Jim Spilker Jr., Todd Walter, Per Enge, and Anthony Pratt, Code Generation Scheme and Property Analysis of Broadcast Galileo L1 and E6 Signals, ION Global Navigation Satellite Systems Conference 2006, Fort Worth, Texas, September 2006. [pdf]

Grace Xingxin Gao, Zhe Xiang, Hao Wang, Jun Shen, Jian Huang, and Song Song, An Approach to Security and Privacy of RFID System for Supply Chain, IEEE International Conference on e-Commerce Technology for Dynamic e-Business 2004, Beijing, China, September 2004.

Grace Xingxin Gao, Richard Yao, and Zhenming Feng, Hadamard Coded Multi-bandUWB, IEEE Semiannual Vehicular Technology Conference (VTC) 2003, Orlando, Florida, October 2003.

Richard Yao, Grace Xingxin Gao, Zhengqi Chen, and Wenwu Zhu, UWB Multipath Channel Model Based on Time-Domain UTD Technique, IEEE Global Communications Conference GLOBECOM 2003, San Francisco, California, December 2003.

Grace Xingxin Gao, Lu Mingquan, and Feng Zhenming, Asymmetric Hexagonal QAM Based OFDM System, IEEE International Conference on Communications, Circuits and Systems and West Sino Expositions 2002, Xi'an, China, June 2002.

Grace Xingxin Gao, Lu Mingquan, and Feng Zhenming, Optimal Wavelet Packet Based Multicarrier Modulation over Multipath Wireless Channels, IEEE International Conference on Communications, Circuits and Systems and West Sino Expositions 2002, Xi'an, China, June 2002.

Invited Talks