Aerial Image Matching Based Relative Localization of a UAV in Urban Environments

This paper presents a method for localizing an Unmanned Aerial Vehicle (UAV) using geo-referenced aerial images, in case of GPS failure. When flying in urban environments in low altitudes the inaccurate GPS localization has become a major problem. The proposed method fuses measurements from inertial sensors and visual odometer and perform image registration process using the images captured by the onboard down looking camera. A pre-built local orthomosaic map with geotagged aerial images is used for the registration. The problem of unreliable matches caused by the dynamic objects is addressed in our approach. The experiment results show that it is possible to localize the UAV in urban environments with a low margin of error by using our method.