GNSS and robot localization

The Global Navigation Satellite System (GNSS) is the most famous and spread-out system for mobile localization outdoor. This chapter is devoted to satellite navigation and its application for mobile robots. GNSSs enable an Earth-located receiver to determine its absolute position in space. This is done by measuring the receiver’s distance to the navigation satellites and extracts its location from those distances. The most famous GNSS is the US global positioning system (GPS). The most used geographic coordinate system in GNSS receivers is based on latitude, longitude, and altitude. Another popular system for mobile robots is the grid-based Universal Transverse Mercator projection. GNSS devices tend to perform poorly in urban canyon environments. A GNSS device would simply use four (or more) strong enough signals to compute its estimated location. Any GNSS receiver requires the satellite information in order to function properly. The chapter discusses three types of GPS systems: aided-GPS, differential GPS, and real-time kinematic navigation.