Skip to main content

GeoXO Ocean Color Instrument (OCX)

Image of the cloud coverage over the Western United States
Of the 17 days shown in the animation above, only 30-35% (5-6 day) have sufficient data to resolve oceanic dynamics. Geostationary ocean color would provide significantly greater daily spatial coverage. Credit: NOAA NFMS

NOAA plans to include a hyperspectral, ultraviolet through near-infrared passive imaging radiometer that analyzes ocean data as part of the GeoXO satellite system. The GeoXO Ocean Color (OCX) instrument is planned to achieve 390-meter spatial resolution.

OCX will observe ocean biology, chemistry, and ecology to assess ocean productivity, ecosystem change, coastal and inland water quality, seafood safety, and hazards like harmful algal blooms (HABs). OCX will analyze ocean data within the U.S. Economic Exclusive Zone (EEZ) and Great Lakes at least every three hours. Frequent observations will show daily changes in ocean biology and rapid coastal ocean dynamics. The instrument will also track and assist in the response to climate-driven ocean and coastal ecosystem changes.

Improvements Over Current Capabilities

Satellite image of Florida and part of the Atlantic Ocean and Gulf of Mexico. Coastal waters are a milky, aquamarine color due to sediment. Browner hues are runoff.
When Hurricane Dorian passed over the Bahamas and along the southeastern U.S. coastline, its waves resuspended large quantities of sea-floor sediment, which give the ocean a milky, aquamarine appearance in this composite of VIIRS data collected on Sept. 7, 2019. The browner hues closer to the U.S. shore come from runoff generated by heavy rainfall from the hurricane. Credit: NOAA

Having an ocean color instrument onboard a geostationary satellite like GeoXO will provide a comprehensive view of the U.S. Economic Exclusive Zone (EEZ) and Great Lakes. NOAA defines an EEZ as an area of the ocean, generally extending 200 nautical miles (230 miles) beyond a nation's territorial sea, within which a coastal nation has jurisdiction over both living and nonliving resources. NOAA is mandated to support the stewardship of 479 fish stocks and 164 endangered and threatened species throughout the 3.4 million square mile U.S. EEZ.

OCX will deliver a more frequent and comprehensive view of ocean and coastal conditions than is currently available. From its position in geostationary orbit, OCX will provide observations at least every three hours, while current low-Earth-orbiting sensors provide updates only once per day. More frequent images will greatly improve the chance of cloud-free observations over of areas of interest. Cloud cover often obscures the view from space and having many images of the same scene per day provides more opportunity for a clear picture and an accurate representation of real-time conditions. More timely data will allow scientists to asses both daily changes in ocean and coastal conditions and track rapidly-changing features like sea fog and oil spills. With fast image updates, OCX promises to mitigate cloud cover issues over the U.S. Pacific coral reefs. Today, NOAA can image only one out of five coral reefs due to cloud cover. This impacts NOAA’s ability to manage reef systems, such as the Hawaiian Coral Reefs, valued at $33.57 billion.  

OCX will have a higher spectral resolution than the Joint Polar Satellite System (JPSS) Visible Infrared Imaging Radiometer Suite (VIIRS) and NASA's Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission.  High-resolution ocean color imagery will improve observations of water clarity and chlorophyll concentration as well as provide better detection of harmful algal blooms and coastal pollutants. Finer resolution will also allow scientists to better monitor water quality within smaller bodies of water and along the coast where urbanization and high nutrient runoff have an increasingly negative impact on the livelihoods of local communities.

Unlike current ocean color sensors, OCX is a hyperspectral instrument that will analyze a wide spectrum of light from ultraviolet to near-infrared. The additional spectral information will be critical for distinguishing types of phytoplankton to support aquaculture activities and for tracking algal blooms in coastal waters, which are more complex due to dissolved pigments and sediment.

Benefits of a Geostationary Ocean Color Instrument

Frequent, high-resolution ocean color imagery will help NOAA provide more accurate and timely forecasts and scientific guidance to federal, state, and local agencies. OCX observations will support ecological forecasters, marine resource managers, fisheries, health departments, water treatment managers, and the commerce, recreation, and tourism industries.

Public Health

OCX observations will contribute to NOAA forecasts of HABs. NOAA monitors conditions daily and issues forecasts for HABs in support of the tourism industry and public health, including respiratory issues. 

Fishermen with raincoats and hats unload a halibut catch from a fishing vessel.
Fishermen unload halibut catch. Credit: NOAA

Commercial and Recreational U.S. Fisheries

OCX will provide better predictions and scientific advice for decision-making about valuable sustainable fisheries and protected resources. Early warning would allow for mitigation to protect shellfish stocks and ensure public health safety. 

Improved Data Resolution

The instrument’s 390-meter spatial resolution will help NOAA provide more accurate and timely forecasts and scientific guidance to federal, state, and local agencies about rapidly emerging coastal hazards such as harmful algal blooms. 

Improved Determination of Phytoplankton Functional Types

OCX data will provide new indicators of ecosystem production, refine estimates of the overall fisheries yield, and advance HAB forecasting.

Improved Timing of Harmful Algal Bloom Events

It is estimated that the acute health effects associated with marine pathogens and HAB toxins cost almost $1 billion per year. Improved ecological forecasts improve mitigation and decision-making, reducing both costs and effects of events and longer-term changing conditions. Improved forecasts provide more time for mitigation and predicting when conditions will return to normal (e.g. allowing shellfish closures to be lifted as quickly and safely as possible).

Improved Ecological Forecasts

OCX will provide improved ecological forecasts for state fisheries, state health departments, water treatment managers, local commerce and tourist industries, and recreational and commercial fisheries and shellfisheries.

Monitoring Land-Based Pollution

Land-based sources of pollution (LBSP) from coastal development, deforestation, agricultural runoff, and oil and chemical spills produce many serious coral reef ecosystem stressors, most notably toxicants, sediments, and excess nutrients. These can impede coral growth and reproduction, disrupt overall ecological function, and cause disease and mortality in sensitive species. LBSP is typically caused by coastal and upstream land development (but can also form from natural land erosion). It is identifiable by a significant increase in water turbidity (the measure of relative clarity of a liquid), especially following significant precipitation events that result in plume events. Ocean color data is used to track LBSP by identifying plume signatures, which helps identify health threats to coral reef ecosystems. With the improved temporal (hourly) and spatial (300 m) resolutions OCX will offer, scientists and watershed managers will see LBSP events unfold and could respond more quickly, leading to more effective response rates.

NOAA’s land-based sources of pollution value chain

OCX Value Assessment Report

Learn more about the benefits of geostationary ocean color observations in NOAA’s Technical Report: The Value of Geostationary Ocean Color

OCX Status

On May 26, 2022, NASA selected Ball Aerospace & Technologies Corp. of Boulder, Colorado, and Raytheon Intelligence & Space of El Segundo, California, to conduct OCX Phase A Studies. Each company conducted a definition-phase study of a geostationary ocean color instrument and submitted a final report in June 2023.

The results of these studies were used to set performance requirements for the OCX instrument development contract. NASA posted the request for proposals for OCX development on Aug. 31, 2023. NASA plans to select a development contractor for OCX in late March 2024.

Related Links

The information on this page is subject to change as the GeoXO program develops.