  Micro aerial vehicles (MAVs) exhibit high potential for information
extraction tasks in search and rescue scenarios. Manually controlling MAVs in
such scenarios requires experienced pilots and is error-prone, especially in
stressful situations of real emergencies. The conditions of disaster scenarios
are also challenging for autonomous MAV systems. The environment is usually not
known in advance and GNSS might not always be available.
  We present a system for autonomous MAV flights in unknown environments which
does not rely on global positioning systems. The method is evaluated in
multiple search and rescue scenarios and allows for safe autonomous flights,
even when transitioning between indoor and outdoor areas.
