Unlike ground vehicles, micro aerial vehicles have the 3D maneuverability, which enable them to perform a lot of risky tasks in environments where humans cannot get access to. For tasks such as surveillance, rescue and reconnaissance, micro unmanned aerial vehicles(UAV) must be able to navigate without any prior knowledge of the scene map. In order to solve the navigation problem for micro UAV in unstructured environments where there is no GPS signal, we investigate a position and attitude measurement metho...