# Three-Dimensional Real-Scene-Enhanced GNSS/Intelligent Vision Surface Deformation Monitoring System
## 2 Deformation Monitoring System Architecture  
The system adopts a three-layer architecture of \"edge collection-cloud fusion-terminal interaction\" (Figure 1) to facilitate the collection, transmission, and visualization of GNSS data, meteorological data, and video data [22; 23].  
The edge collection layer performs multimodal data acquisition. The GNSS terminal outputs latitude, longitude, elevation, and UTC time by 4G wireless transmission. The visual sensor pushes an H.264-encoded video stream through the RTMP protocol. The weather station reports temperature, humidity, wind speed, wind direction, rainfall, and barometric pressure through the MQTT protocol (JSON format, 5s interval). The UAV with a tilt camera system collects multi-view images and generates a high-precision 3D grid model with ContextCapture 10.20 software [24; 25]. The Trimble SX10 imaging station acquires high-density point cloud data with millimeter-level accuracy, storing data in LAS format to facilitate integration with UAV photogrammetry models [26].  
The cloud fusion layer relies on Tencent Cloud servers for data integration, classification, and storage. It receives RTMP protocol video streams from visual sensors through the lightweight streaming media server ZLMediaKit, which supports multiple concurrent transcoding and HTTP-FLV format distribution. Meanwhile, Nginx static resource servers are deployed to host 3D geographic information data in 3D Tiles format [27; 28]. GNSS data are structured and stored with fields such as device ID, latitude, longitude, elevation, and UTC timestamp. Meteorological data are indexed in tables by dimensions such as sensor node ID, temperature, humidity, and wind speed. The real-time control of the power supply on/off is achieved through the WebSocket server and TCP server.  
The terminal interaction layer integrates real-time video streaming, a 3D spatial model, sensing data, and IoT control functions. Using the CesiumJS 3D engine, it loads 3D Tiles from cloud-distributed tilt camera models, providing functionalities such as 3D scene browsing, calculation, spatial analysis, and dual-screen comparison. RTMP video  
Figure 1: Architecture of the proposed deformation monitoring system. The edge collection layer consists of the GNSS receiver, meteorological receiver, visual sensor, drones, RoboMaster S1, DJI Airport, and 3D Laser Scanning. Data are transmitted, processed, and stored in this layer. The cloud fusion layer uses servers like Tencent Cloud and Nginx for data handling. The terminal interaction layer provides real-time data, live video, augmented reality, historical data, early warning, spatial analysis, report management, 3D-model management, edge detection, and remote control.  
streams (encapsulated as HTTP-FLV by ZLMediaKit) are dynamically superimposed on the corresponding position of the 3D scene through coordinate mapping, forming a dual-view fusion screen of \"live view model + real-time monitoring\" [29; 30]. Users can trigger remote light control commands through interface buttons, driving relays to activate fill lights. Real-time GNSS data are displayed through charts, and meteorological information is displayed through charts or wind disks. The layer also includes warning alerts, report downloads, and historical data queries, forming a closed-loop \"monitoring-warning-control-retrospection\" management system.