Abstract: Most inertial navigation systems are integrated with other sensors in order to remove long-term drift. While GPS is an ideal aiding sensor for inertial systems, there is increasing interest in non-GPS aiding sources to be used in situations where GPS is not available. This tutorial will provide a survey of several different non-GNSS navigation techniques. A variety of non-GNSS alternatives will be covered at the phenomenology level, describing the overall characteristics of each of the possible phenomenologies that can be used to navigate, including the limits of performance that result from use of these phenomenologies (where they can be used, when they can be used, expected accuracies, etc.). Then, for some of the more common approaches, we will describe some of the practical implementation issues that are faced when implementing a real-world system. Examples of phenomenologies useful for navigation to be covered include vision, signals of opportunity, lidar, pseudolites/beacons, magnetic field variations, and star trackers.