## 4 Core Insights and Critical Reflections
### Expansion and Deepening of Application Fields  
The application fields of UAV-RS technology are constantly expanding and deepening with the evolution and breakthroughs of its key technologies. Initially dominated by military reconnaissance, UAV-RS has gradually penetrated into all aspects of civilian fields and is playing an increasingly important role in many industries (Table 9). Its high flexibility, high resolution, low cost, and rapid response capabilities make it a powerful complement to traditional aerial and space remote sensing, and even show irreplaceable advantages in some specific applications. The robust growth of the UAV-RS market also reflects the extensive expansion and deepening of its application fields. \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Application Fields** & **Main Application Contents** & **Key Technologies/Sensors** \\ \hline Military Reconnaissance and Security Surveillance & Intelligence collection, battlefield surveillance, target location, damage assessment, border patrol, counter-terrorism operations, inspection of critical infrastructure, and security for large-scale events. & High-definition cameras, thermal infrared sensors, Synthetic Aperture Radar (SAR), and signals intelligence equipment. \\ \hline Precision Agriculture & Crop growth monitoring, pest and disease identification and control, yield estimation, variable fertilization and irrigation, farmland environment monitoring, and crop phenotyping analysis. & Multispectral/hyperspectral sensors, thermal infrared sensors, RGB cameras; deep learning. \\ \hline Forestry and Pasture Management & Forest resource investigation, tree species identification, forest fire monitoring and assessment, pest and disease monitoring, wildlife habitat investigation, grassland productivity assessment, and biomass estimation. & LiDAR, multispectral/hyperspectral sensors, RGB cameras. \\ \hline Environmental Monitoring and Assessment & Atmospheric pollution monitoring, water body eutrophication and black-odorous water body monitoring, soil erosion and desertification investigation, wetland ecosystem monitoring, gas sensors (DOAS), LiDAR. monitoring, and oil spill accident emergency monitoring. & Multispectral/hyperspectral sensors, thermal infrared sensors, gas sensors (DOAS), LiDAR. \\ \hline Disaster Emergency Response and Management & Rapid disaster assessment, mapping of the affected area, personnel search and rescue, investigation of lifeline engineering damage, and secondary disaster monitoring and early warning. & High-definition cameras, thermal infrared sensors, LiDAR, SAR. \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Expansion and deepening of the main application fields of UAV-RS. (1) Military reconnaissance and security surveillance are one of the earliest and most important application fields of UAV-RS. UAVs are capable of penetrating into enemy territory or high-risk environments to conduct intelligence collection, battlefield surveillance, target location, and damage assessment, effectively reducing casualties. For example, the United States Coast Guard has routinely deployed UAVs equipped with ISR (Intelligence, Surveillance, and Reconnaissance) sensors on National Security Cutters to build maritime situational awareness and support law enforcement missions and search and rescue operations [160]. Small UAVs like the \"Black Hornet\" are also used for military reconnaissance, providing local situational awareness for ground troops [161]. (2) Precision agriculture is one of the most active and mature fields of application for UAV-RS technology. UAVs can be equipped with multispectral and hyperspectral sensors to quickly obtain key agronomic parameters such as crop growth conditions, Leaf Area Index (LAI), and Above-Ground Biomass (AGB), providing a scientific basis for precision fertilization, variable rate pesticide application, pest and disease monitoring, and yield estimation [162].