Salv AIoT Platform for Mountain Accidents Prevention and Search and Rescue Missions

Between 2015 and 2022, the Mountain Rescuers Romanian Association conducted over 57,000 search and rescue (SAR) operations, addressing incidents primarily caused by route deviation, failure to adapt to environmental conditions, and natural disasters. However, SAR operations in remote mountainous areas face significant challenges due to limited connectivity and the lack of an integrated platform linking users and SAR teams. This paper introduces the SalvAIoT platform addressing these challenges by equipping tourists and SAR unmanned vehicles with low-power, long-range communication technology devices, sensors, state-of-the-art embedded systems, and innovative TinyML algorithms for route assistance and victim localization. Additionally, the paper designs five practical scenarios for SalvAIoT use cases, involving end-devices (ED) for users and unmanned aerial and surface vehicles (UAV s, USV s) able to provide connectivity in harsh environments. Furthermore, the paper investigates the impact of antenna position deviation, UAV antenna height, and USV and ED position on the communication link. Experimental results show that LoRa technology can provide a detection range of 437.2 m for a direct link between user ED and UAV, 310.5 m for ED-USV, and 480 m for UAV-USV link when using the smallest spreading factor. Moreover, the paper highlights that increasing the UAV's altitude from 30 m to 80 m results in a maximum difference of 8 dB for distances below 250 m. However, for distances between 250 m and the maximum coverage range, similar or better Received Signal Strength Indicator (RSSI) characteristics were observed when the UAV's height was 30 m. To conclude, LoRa emerges as a promising technology for providing network coverage for the Salv AIoT platform, facilitating mountain accident prevention and intervention, particularly when employing unmanned vehicles.