# A Comprehensive Review of Indoor Localization Techniques and Applications in Various Sectors
## 1 Introduction
The Pouect system addresses this by combining technologies like GPS, LoRa, UWB, and altimeters in a hybrid architecture. By strategically deploying nodes during operations, the system ensures reliable localization in challenging conditions [23]. To overcome these challenges, a range of technologies and strategies are being implemented. UWB technology, operating in the 3.5-6.5 GHz frequency range, is particularly effective in industrial environments due to its ability to minimize interference and offer high-precision localization, even in harsh conditions [24]. Additionally, RFID-based systems are employed for asset tracking and environmental monitoring. For instance, specialized RFID-sensitive tags can detect nanometer-scale corrosion on metallic surfaces, extending the utility of localization technologies to equipment maintenance and environmental sensing [23]. Moreover, innovative algorithmic approaches like particle filtering and sensor fusion can enhance localization accuracy. These methods combine data from various sensors, including inertial measurement units (IMUs), vision systems, and radio-based technologies, to create comprehensive localization frameworks [25]. For example, multisensor systems that employ cellular automata particle filtering can dynamically adjust the weighting of sensor data based on real-time performance metrics. This capability allows robots and automated machinery to navigate complex industrial environments with high reliability [26]. In healthcare, these technologies improve the real-time tracking of patients, staff, and medical assets, enhancing workflow efficiency and patient safety. BLE and IoT-based RTLSs provide accurate localization in hospitals, while HAR systems enable the monitoring of mobility-impaired or elderly patients using wearable sensors [27; 28]. In military and emergency response operations, hybrid localization systems and adaptive sensor fusion frameworks ensure robustness and flexibility [29]. Systems like Project Sentinel employ hard, soft, and predetermined fusion techniques to maintain reliable tracking in dynamic and unpredictable scenarios. This ensures that commanders have real-time position data, enabling faster response times, improved resource allocation, and enhanced safety for personnel. Advanced features such as health monitoring, weapon orientation tracking, and after-action reviews (AARs) provide additional layers of functionality for mission planning and analysis [7; 30]. Despite these advancements, challenges remain in terms of scalability, cost-effectiveness, and maintaining accuracy under highly dynamic conditions. In industrial environments, the need for systems that can scale to large facilities while remaining affordable is critical [31]. AI-driven analytics, sensor fusion, and advanced encryption protocols will play pivotal roles in overcoming these challenges. AI can improve accuracy by identifying patterns and compensating for errors, while robust cybersecurity measures protect against data breaches and unauthorized access [32; 33]. As research continues, the focus must be on developing localization systems that are secure, adaptable, and efficient across diverse applications. The integration of these technologies will pave the way for smarter healthcare facilities, more efficient industrial operations, and safer military and emergency response missions [34]. By addressing current limitations, indoor localization systems will ultimately transform how critical sectors operate, improving outcomes and enhancing safety in complex environments [35]. The Poucet system exemplifies a cutting-edge hybrid localization approach by integrating multiple technologies such as GPS, LoRa, UWB, and altimeters into a unified framework [36]. This combination allows for versatile, real-time tracking and reliable localization, especially in GNSS-denied environments where traditional GPS signals are obstructed or unavailable. By strategically deploying nodes during operations, the Poucet system ensures consistent performance even in dynamic and unpredictable settings.