As with most journeys in life, this thesis took me along a pathway that I could have never predicted. It could not have been completed successfully without the invaluable support from several people. Especial thanks to my supervisor, Dr. Sunil Bisnath who provided me with the opportunity to embark on this journey. He never ceased to challenge me, redirected my path after each setback, and always encouraged me to believe in myself as I forged ahead. He also created countless networking opportunities for me through conferences and multiple internships for which I am extremely grateful. Thanks to Dr. Bisnath for his invaluable support with technical advice, financial assistance, and an amicable work environment. I also wish to thank Drs. Jian-Guo Wang, Spiros Pagiatakis and Costas Armenakis for their priceless corridor consultations and insightful feedback. A memorable guest lecture from the late Dr. Kees de Jong in 2013 at York University, Canada led to an internship at Fugro Intersite, Netherlands. The work relationship with Drs. Kees de Jong, Xianglin Liu and Matthew Goode and Ms. Karin Cambier at Fugro was commendable. The experience obtained from this internship augured well with core of my research. Special thanks to the Etienne van der Kuij of ProTanks Group in Rotterdam, Netherlands for the first-hand knowledge gained in assessing the performance of GNSS within the Rotterdam World Gateway (RWG). In 2016, I was selected to serve at the Geodetic Surveying Division of the Canadian Federal Government as part of the Research Affiliate Program (RAP). I am deeply indebted to Dr. Simon Banville, Paul Collins and François Lahaye for their shrewd and skillful supervision. To the pioneers of Precise Point Positioning, Jan Kouba and Pierre Héroux, my direct consultation with them is invaluable. A special thanks to Paul for his innovative techniques in the development of the decoupled clock model which serves as the foundation of this research. I also wish to acknowledge NRCan for providing the base PPP code and PPP expertise. York University was not just a school, but also a home and my colleagues and I became a family. A special thanks to John Aggrey, Amir Saeidi, Amandeep Mander, Surabhi Guruprasad, Maninder Gill and Siddharth Dave. Thanks to John for his contributions to the development of the YorkU-PPP software. Without his support, YorkU-PPP could not have been the powerful tool that it is today. While the journey of a PhD takes a lot of self discipline, dedication and hard work none of it would have been possible without the support of my family. Thanks to Grandma, Mom, Dad, Dawn, Noah, Glenroy, Shiva, Alexandra, Taylia, Shana, Ravi, Damian, Vivek and Vachan. I will always be indebted to them for their prayers, sacrifices and encouragements.