SCSN Advanced Telemetry and Real-Time System Monitoring Tools

The USGS/Caltech Southern California Seismic Network (SCSN) is a modern digital ground motion seismic network. It develops and maintains Earthquake Early Warning (ShakeAlert) data collection and delivery systems in southern California as well as real-time ShakeAlert algorithms. We present recent and ongoing innovations in telemetry, system monitoring, and data analysis that keep the network running efficiently and provide timely high-quality streaming data. We developed tools to monitor the system state of health, including regular measurements of data transport latency, telemetry link bandwidth from each datalogger to the data center (called Telemetry Recovery Test), and packet rates during intervals of different seismic activity. Based on the bandwidth results, we assign a letter grade to each link. It allows us to prioritize improvements for low-performing sites that cannot support the increased packet and data rates well. For newly installed sites, we track if they meet our latency and bandwidth targets. With our Telemetry Recovery Test results we also can predict the connections where problems could appear during a large event. For example, many of the poorly performed sites before the event also performed poorly during the Ridgecrest 2019 earthquake, especially in the 35 km radius from the epicenter. We continue to improve the telemetry path diversity, minimize data transfer latency, and increase available bandwidth. We are in the process of connecting the SCSN sites to the California State Microwave Tower backbone. This microwave network will acquire data streams from approximately 100 sites, which will improve speed and completeness of data delivery.