Naval Oceanography: At The Leading Edge of Unmanned Systems
13 March 2023
STENNIS SPACE CENTER, Miss. - One of the premier innovators of the fields of meteorology and oceanography, the Navy is also a trailblazer in unmanned systems, notably METOC's use of air, sea surface, and underwater craft.
The U.S. Navy’s development of unmanned systems dates to the Pioneer Era of Aviation. In 1911, the Navy contracted Elmer Sperry, inventor of the gyroscope (critical for stabilization of all aircraft, manned and unmanned), to begin work on systems that would be used to usher in the first controlled unmanned airplanes. In September 1917, during the height of World War I, the Hewitt-Sperry Automatic Airplane, which the Navy called an “aerial torpedo,” took flight. The craft was one of the first unmanned aerial vehicles in history to fly. Just a few years later, in 1921, the Navy repurposed the battleship USS Iowa (BB-4) as a remotely controlled craft. Officially designated “Coast Battleship No. 4,” the vessel, one of the world’s first military unmanned surface vehicles, was used as a target ship. Decades later, the Navy helped develop, fully funded, and operated the world’s first underwater unmanned vehicle. Called the Self-Propelled Underwater Research Vehicle, or SPURV, the program began in 1957 and was used to gather hydrographic information.
METOC has developed, and continues to refine, technology that traces its lineage to these decades-old progenitors. Today, the command operates and sources data from an extensive fleet of some of the most advanced unmanned systems ever developed. These systems are critical for the Department of Defense to maintain readiness and up-to-the-minute environmental situational awareness, notably in strategic locations on the globe that are “data sparse” due to their lack of long-term, persistent sensors. These include a multitude of aircraft systems, sea surface systems, and underwater craft that collect relevant atmospheric and oceanographic data and transmit it for processing. Unmanned aircraft that can supply data to METOC include the large MQ-4C Triton, the Navy variant of the Global Hawk. The platform, which has a wingspan of 130 feet, 11 inches, can operate for more than 24 hours and at altitudes up to 56,000 feet above sea level (the system has flown over active hurricanes). METOC also sources data from smaller unmanned aerial vehicles, including hand-launched systems and high-altitude balloons. One of the most valuable aerial tools used by the command is the dropsonde, a small unmanned system that can be deployed from either a manned or unmanned aircraft. The dropsonde falls through the atmosphere, slowed by a parachute, and its position is continuously recorded by GPS. It collects and transmits temperature, pressure, and humidity profiles along its descent. Data gathered by dropsondes allow METOC to quickly develop detailed 3-dimensional models of the atmosphere, in near real-time. Sea surface systems employed by METOC include a number of small systems that can function autonomously, called autonomous surface vehicles. These collect data in the atmosphere, on the sea surface, and underwater. Some of these are high endurance vessels, notably those powered by wind and solar energy. METOC also operates a large array of fixed and drifting buoys that collect and transmit both hydrographic and atmospheric data. “Profile floats” are systems that, through using buoyancy control with oil, automatically dive into the depths, collect data on the way down and then on the way up, and then transmit this data via satellite link once at the surface. Plying the depths beneath the surface of the world’s oceans, the command operates a fleet of underwater vehicles. Called AUVs, or autonomous underwater vehicles, these are direct descendants of the SPURV. One of the AUVs operated by METOC, the REMUS (Remote Environmental Measuring UnitS), can operate at depths of 20,000 feet and has an endurance of 30 hours.
METOC recently acquired a “Superior Class” AUV, the HUGIN. This vehicle, based on a carbon fiber monocoque body, can carry a wide suite of sensor systems, has a range of 1,350 miles, and can operate for up to 24 hours and at depths approaching 20,000 feet. METOC also operates a fleet of “ocean gliders,” a highly specialized type of unmanned underwater system that can gather data for up to six months straight and can autonomously cross entire oceans. A glider resembles an airplane, with a long, narrow body, swept wings, and a simple tail section. Powered by batteries, the highly-efficient system uses buoyance control, via oil bladders, to repeatedly rise and sink in the seas. Vertical motion is converted to forward travel, care of the wings, and the system can steer itself into an area of interest, despite currents. A glider transmits its collected data each time it surfaces, the frequency of which is programmable from hours to days. While unmanned systems have existed for decades, many components of the Department of Defense haven’t widely adopted them into operational use until relatively recently. METOC is an exception to this, as it has included unmanned systems in its core suite of sensor platforms for decades. As such, it has developed leading-edge capabilities to manage not just large volumes of data, but large numbers of independently-operating remote platforms. Furthermore, it has pioneered mechanisms to integrate the volumes of data sourced from myriad unmanned systems with collections from manned platforms and satellites for the creation of accurate, timely environmental information products for American and ally forces operating anywhere on the planet. “Naval Oceanography has successfully employed and operated unmanned systems for over 20 years, and, while unmanned systems applications are broad, we leverage these types of capabilities to characterize the physical environment, improve our modeling and predictions to fully inform decisions,” summarized Rear Admiral Ron Piret, Commander, Naval Meteorology and Oceanography Command, about METOC’s unmanned systems capability.