O'Keefe, KyleWinit, Rasika2013-12-132014-03-152013-12-132013http://hdl.handle.net/11023/1194The new GNSS constellations such as Galileo and BeiDou being planned and launched will result in a greatly increased number of available ranging sources, hence, improvement in constellation geometry and coverage. When using signals from multiple constellations, however, the challenges are not only to maximize the benefit from the additional ranging observations but also to deal with the differences among satellite systems such as the time-offset between the constellations. Also, challenges exist when using the ranging signal in GNSS degraded environments where GNSS users potentially see a limited number of satellites from multiple GNSS constellations. This work investigates the accuracy and reliably of position solutions when using ranging signals from combined GPS, GLONASS, BeiDou and Galileo constellations in urban environments. Furthermore, this study assesses the benefits of using a priori inter-system clock-offset information. The positioning performance of multiple GNSS constellations has been examined through covariance simulation and with live data. The benefit of using a priori clock-offset constraints has been demonstrated. It has been found that the benefits of using a priori clock-offset constraints to help enhance the availability of position solutions and fault detection and exclusion capabilities are particularly significant when the receiver is located in areas where limited GNSS signals are available such as in the urban-canyon environment.engUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.EngineeringGNSSGPSGLONASSGalileoBeiDoumaster thesis10.11575/PRISM/26219