Utilizing Uncrewed Surface Vehicles (USVs) in Operational Buoy Networks

NOAA’s National Data Buoy Center (NDBC) is utilizing uncrewed surface vehicles (USVs) as an alternative observing platform for moored buoys. This concept of operations explores platforms that are easy to deploy or obtained as an observational data buy service to mitigate outages in critical areas of the coastal United States. Benefits of utilizing USVs include the ability to sustain and improve the NDBC observing network by leveraging observations through public-private partnerships to protect the New Blue Economy while also demonstrating NOAA’s commitment to operationalize uncrewed maritime systems (UMS) within established observational networks.

Beginning in September 2023, one Saildrone platform was deployed off the U.S. West Coast in the Monterey Bay National Marine Sanctuary to replace the buoy at station 46012, Half Moon Bay. Data from Saildrone Explorer SD-1073 (WMO ID 1801589) was released starting 09/01/2023 00:00 UTC. A second Saildrone Explorer, SD-1063 (WMO ID 1801583), was subsequently deployed and replaced SD-1073 on 04/26/2024 00:00 UTC due to navigational issues. SD-1063 was then replaced by SD-1077 starting on 07/27/2024 12:00 UTC, again due to navigational issues.

The Saildrone Explorer vehicles provide similar observations to those of an NDBC buoy. They measure air temperature, relative humidity, wind direction, wind speed, wind gust, barometric pressure, sea surface temperature, significant wave height, and dominant period. The nature of the Saildrone platform does not easily allow for mean wave direction or spectral wave data to be measured. The Saildrone reports their data to NDBC once per hour, while the NDBC buoys report their data every 10 minutes with the wave data reported once per hour.

NDBC has operated Saildrone vehicles in different environments with mixed results. A project in 2022 deployed two vehicles in the Gulf of Mexico to mitigate buoy outages during hurricane season, where the ability of the vehicle to stay on station was limited due to low winds and strong ocean currents. The current project along the U.S. West Coast has proved more successful, with only two short excursions off station due to vehicle issues since the start of the project.

Data from the Saildrone are sent to NDBC for processing and distribution. The data are ingested into the NDBC real-time processing system, quality controlled, and pushed to the Global Telecommunications System (GTS) for ingestion into the global weather enterprise. In addition, all Saildrone data are publicly released on the NDBC website. By controlling the processing and distribution, NDBC ensures the timeliness of critical data processing and delivery and archival, allowing the scientific community to access the information in perpetuity. The NDBC processing system provides a trusted baseline of observation data to be used by the public or industry in applications utilizing artificial intelligence (AI) or machine learning (ML) technologies.