TPOS Uncrewed Surface Vehicles
Overview
Uncrewed surface vehicles (USVs) are semi-autonomous vehicles which are used to collect high-resolution oceanographic and atmospheric data over large-scale distances. The Saildrone is an example of a USV which is currently being tested by the OCS group for integration into the Tropical Pacific Observing System (TPOS). Through these missions, we have tested their readiness level and have developed adaptive sampling strategies for:
- Providing physical and biogeochemical air-sea interaction data in the Tropical Pacific, with near-realtime data for operational meteorological and ocean data centers
- Resolving fast mesoscale air-sea interaction processes (such as atmospheric cold pools associated with convective downdrafts) through a "mobile mesonet" cluster of drones
- Resolving abrupt fronts and their impact on air-sea interactions
- Observing highly variable equatorial upwelling
- Performing interoperability experiments with TPOS surface moorings
- Incorporating biological measurements critical to fisheries management (e.g. biomass distribution) into the multidisciplinary observing capabilities of the USV
This work has been supported by NOAA/OMAO/UxSOC and NOAA/OAR/GOMO.
For additional photos, please check our Saildrone Gallery.
Various data delivery options exist on our Data Access webpage, and realtime data from past and current missions can be accessed via a newly developed Plotly Dashboard.
OCS Saildrone Missions
TPOS 2024 Mission: October 30, 2024 - February 4, 2025
Mission 7 launched on September 16, 2024, with two Saildrone departing Alameda, CA for the first way point, the official start of the mission, in the eastern tropical Pacific at 10°N 125°W. The 98-day mission followed the GO-USV route with a meridional transect from 10°N 125°W to 6°N 125°W before heading southwest to ~138°W, where a coordinated Tropical Instability Wave study with a Seaglider (PI & Pilot: Katie Kohlman, UW) and the NSF-funded UW/APL Wirewalkers was performed, followed by a buoy intercomparison and equatorial upwelling study at 0°N 140°W. The saildrones were then carried westward by the strong currents associated with La Niña, and then headed north to the ITCZ and transited eastward along the North Equatorial Counter Current, ending near 5°N 140°W.
TPOS 2023 Mission: June 22, 2023 - November 5, 2023
Mission 6 began sea trials on May 24, 2023 and officially launched on June 22, 2023, with three Saildrone departing Hawaii on a 120-day mission to the Equator at 155°W to conduct physical and fish biomass surveys across the central tropical Pacific. An intercomparison with the WHOTS mooring was conducted from May 30 - June 2, 2023 for data verification.
TPOS 2022 Mission: June 22, 2022 - September 26, 2022
Mission 5 launched on June 22, 2022, with two Saildrone positioned near 10°N, 125°W, initiating the fifth mission to address the gaps of the current TPOS.
TPOS 2021 Mission: July 23, 2021 - February 17, 2022
Mission 4 launched on July 23, 2021, with two Saildrone departing San Francisco Bay, California, on a mission to the Eastern Tropical Pacific hurricane genesis region and equator at 110°W.
TPOS 2019 Mission: June 8, 2019 - December 8, 2019
Mission 3 also had four Saildrone launched from Hawaii, on June 8, 2019, initiating the third TPOS mission.
TPOS 2018 Mission: October 3, 2018 - February 2019
Mission 2 was initiated with the launch of 4 Saildrone out of Hawaii in October 2018.
TPOS 2017 Mission: September 1, 2017 - May 18, 2018
Mission 1 began with two Saildrone departing Alameda, California, on a mission to the equator and back, in an effort to improve the Tropical Pacific Observing System (TPOS).
Other PMEL Saildrone Missions
ITAE 2018: June 30 - October 6, 2018
ITAE 2017: July 16 - September 29, 2017
ITAE 2016: May 23 - September 3, 2016
ITAE 2015: April 23 - July 28, 2015
Technical Development
PMEL began a partnership with Saildrone, Inc. in 2014, under a Cooperative Research and Development Agreement. The partnership aimed to develop the unmanned surface vehicles to collect high quality oceanic and atmospheric observations.
In addition to the vehicles themselves, Saildrone, Inc. provides engineering expertise in vehicle design, software, electronics, and operations. PMEL provides engineering expertise on sensors, sensor sampling schemes, telemetry protocols, and access to calibration equipment and facilities.
Vehicles being assembled at Saildrone, Inc. (Photo credit Saildrone, Inc.)
The OCS group has been working together with PMEL engineers and Saildrone, Inc. since mid-2016. The OCS goal was to install sensors on the drones with equivalent or better quality than those currently used on Tropical Atmosphere and Ocean (TAO) buoys for air-sea flux measurements. New additions made to the Saildrones also included a 300-kHz Acoustic Doppler Current Profiler for upper ocean current measurements, and a suite of biogeochemical sensors.
Refer to the Technical Notes page for documentation of the OCS / Saildrone development efforts.