This book provides an introduction to navigation based on global navigation satellite systems, to inertial navigation, and to integrated navigation systems, which can be easily understood, and which is written with clarity. The focus is on the principles and on the underlying theory. The reader who is interested in signal processing to get most out of appropriate measurements can directly apply the methods described. Furthermore, based on the fundamentals provided, the reader can, for example, evaluate navigation systems designs, or, under consideration of the references given, further study and investigate specific areas of interest.