Indoor location systems in emergency scenarios: A Survey <s> CONCLUSIONS AND FUTURE WORK <s> The availability of a reliable and precise tracking system for relief units operating in mission critical scenarios would drastically improve the situational awareness and thus facilitate the mission planning and accomplishment as well as increase the safety of human resources. Thus, the demand for such a system is very high both in the military and in the emergency and crisis intervention domain. While there are solutions like GPS for the localization in open areas, problems arise in urban scenarios and indoors due to insufficient or failed signal reception. For indoor use, multiple alternative localization concepts exist that are suited for different use cases and expose varying properties in precision, complexity and required preconditions. The deployment within mission critical scenarios implicates explicit restrictions and requirements so that only some of the techniques are adept or have the potential of being used here. This article identifies the commonly issued requirements to an indoor tracking in mission critical scenarios and introduces basic techniques for position estimation. Subsequently, existing indoor tracking systems specifically in the field of mission critical scenarios are reviewed with a focus on their capabilities in terms of reliability and accuracy. By doing so, an overview of current approaches in this field is given. Furthermore, the most adept techniques are classified with respect to the requirements within mission critical scenarios. <s> BIB001 </s> Indoor location systems in emergency scenarios: A Survey <s> CONCLUSIONS AND FUTURE WORK <s> A robust, accurate positioning system with seamless outdoor and indoor coverage is a highly needed tool for increasing safety in emergency response and military urban operations. It must be lightweight, small, inexpensive, and power efficient, and still provide meter-level accuracy during extended operations. GPS receivers, inertial sensors, and local radio-based ranging are natural choices for a multisensor positioning system. Inertial navigation with foot-mounted sensors is suitable as the core system in GPS denied environments, since it can yield meter-level accuracies for a few minutes. However, there is still a need for additional supporting sensors to keep the accuracy at acceptable levels during the duration of typical soldier and first responder operations. Suitable aiding sensors are three-axis magnetometers, barometers, imaging sensors, Doppler radars, and ultrasonic sensors. Further more, cooperative positioning, where first responders exchange position and error estimates in conjunction with performing radio based ranging, is deemed a key technology. This article provides a survey on technologies and concepts for high accuracy soldier and first responder positioning systems, with an emphasis on indoor positioning. <s> BIB002
This work presented a survey of indoor location systems focused on emergency situations. First related works were presented, highlighting a similar survey BIB001 . Thus, we detailed the research protocol. The main indoor location techniques were presented, categorized by used signal, measure method and infrastructure need. The contributions of this survey are: a a list of requirements for indoor location systems in emergency scenarios; a list of indoor location systems, classified according to used signal, protocol, infrastructure exigency, analysis method, target user and reported accuracy. The requirements were used to compose a questionnaire that will be applied to specialists in emergencies. Future work includes finalize and report the results of experts questionnaire, analyze the requirements identified and relate them with the works included in this survey. As stated in Section 5.2, other interesting future works possibilities are: the proposal for standardized test methodologies for indoor location system; the development of co- S BIB002 BIB001 munication protocols for hybrid and ubiquitous location systems; and the research of indoor location systems based on Bluetooth Low Energy. 