A NASA-led project to track changes in water, ecosystems and the Earth’s surface

The first round of OPERA products links visible and infrared measurements from the European Space Agency’s (ESA) Sentinel-2 A/B satellites and from Landsat 8, built by NASA and operated by the US Geological Survey. These tools will soon be augmented with data from cloud-penetrating radars on ESA’s Sentinel-1 A/B satellites and the recently launched Surface Water and Ocean Topography (SWOT) satellite, a partnership between NASA and the French space agency CNES (Centre National spatial studies). OPERA will eventually ingest satellite radar data from the NASA/Indian Space Research Organization (NISAR) Synthetic Aperture Radar (NISAR) satellite, scheduled for launch in 2024.

Surface water mapping

OPERA’s Dynamic Surface Water eXtent product family offers what may be the most comprehensive data source for monitoring lakes, rivers, reservoirs and streams. The first phase relies on Harmonized Landsat Sentinel-2 (HLS) optical data to generate near-global maps of surface water every few days at a spatial resolution of 30 metres. Later phases will use Sentinel-1, SWOT, and NISAR radar observations to map surface waters more often (because radar can penetrate cloud cover).

For example, when a series of nine weather-river events dumped heavy rain and snow on California in the winter of 2022-2023, many flood control levees faced flood risks. Surface water maps prepared by OPERA recorded the dramatic filling of these reservoirs.

Monitor surface turbulence

OPERA products provide new insights into the environmental and geological processes occurring on Earth’s surfaces. Complementing its suite of water products, OPERA’s surface disturbance product uses HLS data to map changes in vegetation. It could be used to monitor scars and regrowth after wildfires, track growing cities, or even detect insect outbreaks in forests.

“We are very excited to use the integrated Landsat and Sentinel-2 data,” said Matt Hansen, a professor at the University of Maryland and OPERA project partner. “The combined observations provide unprecedented power, and we expect an unprecedented record of global land change.”

For example, the Mosquito Fire was discovered on September 6, 2022, and burned mainly in the Tahoe and El Dorado National Forests. OPERA’s surface disturbance data product shows vegetation losses due to the fire — the largest in California of the year — that covered about 76,788 acres and lasted 50 days.

Measuring surface displacement of North America

OPERA’s third product, scheduled for launch in late 2024, will provide a history of the extent to which North American land surfaces have moved or deformed due to geological and human activities. The surface displacement product will map surface movement that would be imperceptible without an extensive network of GPS instruments.

“This is a transformative product for detecting landslides, sinkholes, earthquakes, volcanoes — anything that changes the surface of the Earth,” Bawden said. “Using these satellites, we are able to measure movements on the Earth’s surface to less than an inch. We can begin to explore how these movements affect everything that lives there.

All OPERA products are available to the public. Surface water and surface turbulence products are currently available through NASA’s Distributed Active Archive Centers, the Distributed Active Archive Center for Physical Oceanography, and the Distributed Active Archive Center for Terrestrial Processes, respectively.

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