This book shows in comprehensive manner how the Global Positioning System (GPS) works. The use of GPS for precise measurements (i.e. surveying) is treated as well as navigation and attitude determination. The basic mathematical models for various modes of GPS operations and detailed explanation of the practical use of GPS are developed precisely in this book. Additionally, the text shows why and how the kinematic mode differs from the static mode and exemplifies types of projects where different measurement modes are used. Explanations of proper project planning, execution, data reduction, and coordinate computation are provided for novice GPS users.