Wide-area monitoring is a research field and methodological approach focused on the coordinated collection, transmission, and analysis of data from geographically dispersed locations. It investigates the state, dynamics, and events occurring across large spatial scales. Key characteristics include the deployment of distributed sensor networks, synchronization of data timestamps, and the integration of data streams for comprehensive situational awareness. Its significance lies in enabling enhanced observability, detection of complex phenomena or anomalies not apparent from local measurements, and facilitating informed decision-making for management, control, or research purposes across the monitored area.