Update on NOAA's Development and Test of Measuring Waves with a Radar Tide Gauge

The NOAA Center for Operational Oceanographic Products and Services (CO-OPS) maintains the National Water Level Observation Network (NWLON), consisting of over 200 stations providing real-time water level observations along U.S. coasts. The transition to microwave radars as the primary water level sensors at most stations has allowed for the exploration of the sensor's wave measurement capability and plans to incorporate nearshore wave observations into the network. CO-OPS currently does not operate and maintain any wave measurement systems, but the new radar water level sensors offer a cost-effective way to enhance nearshore wave coverage for navigational safety and ocean research. Previously reported work evaluated the wave measurement capabilities of microwave radars in the CO-OPS inventory [1], [2]. Initial field tests showed that the Xylem WaterLOG H3611 radar, currently deployed at NWLON stations, had an output limited temporal resolution for accurately measuring high-frequency wind waves. However, the Endress+Hauser Micropilot M FMR240 (
$\mathbf{E}+\mathbf{H}$
) radar, which serves as the base sensor component for the WaterLOG, demonstrated better performance in resolving higher-frequency energies without low-frequency aliasing issues. Recent efforts that have followed previous reports involve demonstrating radar water level sensor wave measurement performance at a broader range of coastal environment types and implementing real-time, automated wave processing capability on the field systems data logger. We will provide a detailed description of the latest wave processing and transmission capabilities, along with latest data results from new field stations.