Far-Target Detection System for Outdoor and Indoor Environments

Accurately localizing points of interest is vital for firefighters and first responders for effective surveying and rescue missions. Traditionally, firefighters rely on subjective visual descriptions transmitted via radios, leading to time-consuming and error-prone communication about their locations. This article presents an approach for far target detection (FTD) provided in terms of longitude, latitude, and altitude (LLA) coordinates in environments where GPS signals may not be available. Using LLA coordinates ensures concise communication among team members on their locations and provides a common coordinate reference system between outdoors/indoors. This article discusses the integration of three devices as a foundation for the FTD system. First, it uses zero-velocity-update (ZUPT)-aided inertial navigation systems (INS) via a foot-mounted inertial measurement unit (IMU) for personnel localization. Second, an augmented reality (AR) headset is employed to localize a handheld platform (HP) relative to the foot. Third, HP is used to determine the direction the firefighter is pointing at and to measure the distance to the objects. The system's performance was assessed through five experiments where a subject mapped a static point while walking a straight path demonstrating that the system is capable of achieving mapping precision within 2 [m] for distances on the order of 20 [m] from the target.