Integration of GPS and vision measurements for navigation in GPS challenged environments

This paper investigates into the feasibility of a combined use of Global Positioning System (GPS) and vision-based measurements for navigation in challenged GPS environments such as urban canyons and indoors. In these environments, a GPS-only navigation solution fix is generally not feasible. However, limited GPS measurements (for example, for two or three satellites) may still be available. These limited measurements can be exploited to enhance the efficacy of alternative navigation aids such as vision-aided inertial. This paper presents a method for the combination of limited GPS carrier phase measurements with features that are extracted from images of a monocular video camera. An integrated GPS/vision solution estimates position changes and orientation of the camera´s body-frame; and, initializes ranges to vision-based features. Simulation results and initial experimental results are presented to validate the proposed integration method and demonstrate its performance.