Robot Localization has become a very valuable aspect for robotics in the recent years. First and foremost, the robot must be aware of its own pose in the space in order to accomplish any navigation manoeuvres. Different localization technologies can be chosen according to the environment in which the motion is performed. While GPS is the most widespread approach for outdoor areas, there are various methodologies that can be implemented indoor, e.g. UWB anchors. A seamless transition between the two regions is required in order to achieve localization without discontinuities.