In Chapter 5, we described the techniques used to improve GNSS accuracy by reducing the impact of GNSS error sources. In this chapter, we introduce systems in which GNSS receivers work with other sensors to provide positioning and navigation when GNSS conditions are difficult.
A popular term in this field is "sensor fusion." Increasingly it is not just GNSS, or even GNSS + Inertial Navigation System (INS), it is an amalgamation of any and all available information to create the most robust and accurate solution available in all conditions. All the input technologies, GNSS, INS, cameras, odometers, digital elevation models, range sensors, range sensors (LiDAR and Radar), etc. are taken into account.
Chapter 6: Sensor fusion