Turning navigation signals into global ocean surface wind intelligence

Ian Collett, Senior Principal Investigator

The world's oceans influence everything from hurricane formation and global commerce to military operations and climate forecasting. Yet vast areas of the ocean remain under-observed, creating persistent challenges for weather prediction, maritime awareness and environmental intelligence. As governments and commercial operators seek more timely and comprehensive data, the space industry is exploring new ways to monitor some of Earth's most remote regions.

At Orion, we believe one of the most promising solutions is already in orbit. Through a technique known as global navigation satellite system (GNSS) reflectometry, existing navigation signals can be transformed into powerful tools for measuring ocean winds and sea-state conditions from space.

A GROWING NEED FOR GLOBAL OCEAN AWARENESS

Despite decades of advances in Earth observation, collecting consistent measurements across the world's oceans remains difficult. Accurate surface wind data is critical for weather forecasting, hurricane tracking, maritime operations, climate research and national security missions. However, obtaining those observations at global scale continues to present technical and economic challenges.

Traditional observing systems each have strengths, but they also have limitations. Buoys, while highly accurate, are fixed and offer coverage only in specific locations. Aircraft observations can be valuable but are costly and episodic. Spaceborne radar systems deliver extensive coverage but often require larger, more power-intensive payloads that can limit deployment flexibility.

As demand for timely environmental intelligence grows, the industry is seeking new approaches that can provide global coverage while reducing mission complexity and cost.

TURNING EXISTING SIGNALS INTO ENVIRONMENTAL INTELLIGENCE

Orion's Ocean Surface Vector Winds (OSVW) sensor was developed to address this challenge through an innovative application of GNSS reflectometry. Launched on the Space Test Program Houston 7 (STP-H7) and attached to the International Space Station (ISS), our OSVW sensor collected GPS reflectometry measurements for three years. The mission also demonstrated the ability to miniaturize GPS reflectometry technology to roughly the size of an NFL football.

Unlike traditional radar systems, OSVW does not transmit its own signal. Instead, it uses navigation signals continuously broadcast by GNSS constellations. As those signals reflect from the ocean surface, subtle changes in their characteristics reveal information about wind speed, wave conditions and surface roughness.

By eliminating the need for a dedicated radar transmitter, this approach enables meaningful environmental observations using smaller, lighter and lower-power payloads. The result is a sensing capability well suited for deployment on small satellites and future distributed constellations, enabling more frequent and cost-effective observations across the globe.

FROM CONCEPT TO ORBIT: DEMONSTRATING THE TECHNOLOGY

To validate this approach, Orion developed OSVW through Phase I and Phase II Small Business Technology Transfer programs. The innovative payload was successfully deployed aboard the ISS in January 2022.

The sensor measures approximately 0.3 meters wide, weighs 2.5 kilograms and operates on 8 watts of power. Its GNSS receivers, derived from Orion's existing terrestrial remote ionospheric observatory technology, collect reflected signals through left-hand circularly polarized antennas and simultaneously track multiple reflections across large ocean regions.

EARLY RESULTS AND EMERGING CAPABILITIES

During the payload’s time on the ISS, OSVW collected delay-Doppler maps, a foundational data product in GNSS reflectometry. Orion has enhanced these observations through advanced stare-processing techniques that extract additional information from sequences of measurements while maintaining high spatial resolution.

Early research has demonstrated the potential to estimate ocean wind speeds through a combination of stare-processing methodologies and machine-learning approaches. Researchers are also evaluating the sensor's ability to characterize additional ocean conditions, including wind direction, significant wave height and broader sea-state characteristics.

The results from OSVW are helping to validate the potential of compact GNSS reflectometry systems as a tool for future ocean-monitoring missions.

THE FUTURE OF OCEAN MONITORING

The future of ocean monitoring may not depend on building larger and more complex sensors. Instead, it may come from extracting new intelligence from signals already surrounding Earth.

As satellite platforms continue to shrink in size and cost, GNSS reflectometry offers a path toward more distributed sensing architectures capable of delivering frequent observations across vast ocean regions. By leveraging existing signals and advanced processing techniques, future constellations could provide improved visibility into weather systems, maritime conditions and environmental changes while delivering observations at greater scale and lower cost.

These capabilities have implications far beyond scientific research. More persistent ocean observations could support improved hurricane forecasting, strengthen maritime domain awareness, enhance commercial shipping operations and provide valuable environmental intelligence for defense and national security missions.

Through OSVW and ongoing GNSS reflectometry research, Orion is helping advance a future of more persistent and comprehensive ocean monitoring.

ABOUT THE AUTHOR 

Dr. Ian Collett is a senior principal investigator at Orion, where he researches and develops operational solutions in GNSS reflectometry, GNSS radio occultation and ionospheric science. He joined Orion in 2021 as a full-time staff member and serves as technical lead for ongoing OSVW and GNSS reflectometry projects.