  A map merging component is crucial for the proper functionality of a
multi-robot system performing exploration, since it provides the means to
integrate and distribute the most important information carried by the agents:
the explored-covered space and its exact (depending on the SLAM accuracy)
morphology. Map merging is a prerequisite for an intelligent multi-robot team
aiming to deploy a smart exploration technique. In the current work, a metric
map merging approach based on environmental information is proposed, in
conjunction with spatially scattered RFID tags localization. This approach is
divided into the following parts: the maps approximate rotation calculation via
the obstacles poses and localized RFID tags, the translation employing the best
localized common RFID tag and finally the transformation refinement using an
ICP algorithm.
