Today marks a significant milestone for Xing Liu, a Ph.D. candidate in Electrical and Computer Engineering, as he successfully defended his dissertation titled "GNSS Localization and Attitude Determination via Optimization Techniques on Riemannian Manifolds." The dissertation defense, which was held at King Abdullah University of Science and Technology (KAUST) in the Information Science Lab (ISL), showcased Liu's extensive research in the field of global navigation satellite systems (GNSS)-based localization and attitude determination.
Liu's work is a testament to his dedication and hard work, and it has undoubtedly contributed to the scientific community. His research in GNSS localization and attitude determination has practical applications in various fields, such as aerospace, marine, and land-based navigation systems.
In his dissertation, Liu proposed novel optimization techniques on Riemannian manifolds to resolve integer ambiguity and improve the accuracy and reliability of positioning and attitude determination. He also developed three different methods for GNSS attitude determination, namely array-aided attitude determination based on an oriented sphere manifold, the Riemannian-manifold-based orthonormality-constrained attitude determination (RieMOCAD), and the constrained wrapped least squares (C-WLS) method. These methods have shown remarkable improvements in attitude determination in challenging environments with insufficient tracked satellites, significant multipath interference, and severe atmospheric effects.
Furthermore, Liu proposed a joint solution for real-time kinematic positioning and attitude determination, leveraging the correlation between the two issues to improve the performance of RTK positioning and attitude determination.
Liu's exceptional work could not have been achieved without the guidance and support of his supervisor, Prof. Tareq Y. Al-Naffouri, senior research staff Dr Tarig Ballal and Mohanad Ahmed, and the research team at Information Science Lab (ISL). The ISL team has always been at the forefront of research, and Liu's dissertation adds to the lab's rich history of innovation and excellence. We are proud of Xing Liu for his remarkable accomplishment, and we look forward to seeing him continue to excel in his future endeavors. Congratulations to Xing Liu his outstanding work!
