High-revisit altimetry space infrastructure

At least 30.000 freshwater level measurement points will be made available from space sensors, allowing for a high-revisit (daily updates) system.

BWI constellation partners 

They support the mission 

Inland water levels revisited daily

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constellation of nanosatellites equipped with miniaturized altimeters

Why are daily water levels measurements necessary? 

Existing continental freshwater altimetry missions are not sufficient as slow repeat cycles end up in hydro-climatic disaster blindness. Rivers and lakes water levels are essential variables according to the Global Climate Observing System, which recommends their daily measurements.

The missing link in existing continental freshwater altimetry missions: high temporal resolution

The BWI constellation, of high temporal resolution, is the perfect complement to large-swath hydrological satellites such as SWOT. For example, soon-to-be Sentinel-3 TOPO NG which are both of much higher spatial resolution but of lower temporal frequency.

A breakthrough for hydrology and freshwater resource management operational applications

1-day revisits will be a revolution in Earth Observation, as current satellites repeat cycles are between 10 and 90 days! Daily updated global water level data points will help advance the state-of-the-art on our understanding of the water cycle.

SMASH abstract

We bring hydrological expertise to the table


A legacy of excellence

Immensely inspired by the SMASH concept (SMall Altimetry Satellites for Hydrology), born at LEGOS & designed at CNES (Phase A completed). French Space Agency CNES has a long history of contributing to altimetry missions. They range from TOPEX-Poseidon launched in August 1992 to SWOT launched in December 2022 – two satellites codeveloped with NASA’s JPL. LEGOS (Laboratory of Space Geophysical and Oceanographic Studies) is a joint research unit (UMR5566) under the auspices of CNES, CNRS, IRD and UT3 at the Midi-Pyrénées Observatory in Toulouse (France). The LEGOS research and teaching scientific fields include oceanography and the water cycle in the broadest sense, with the physics of the oceanic, hydrological, cryospheric and atmospheric components, including coastal and climatic components, as well as marine biogeochemistry and geochemistry. The SMASH mission specification was written by a scientific group led by Pr. Denis Blumstein at LEGOS, and SMASH was then developed at CNES until the completion of Phase A in late 2022.

All satellites are on a Sun-Synchronous Orbit (SSO)

Optimized launch & maintenance costs as our architecture requests just 1 launch to set all 10 nanosatellites on the same orbital plane.

A demonstrator for a start, and then a constellation

Initially, a demonstrator of 2 nanosatellites will be launched to validate scientific, technology and commercial assumptions. Then we expect to launch a constellation of 10 nanosatellites to be extended to 80 nanosatellites. This would span over a decade to extend coverage – by shrinking intertracks, and increase revisit rates.

Inland water level measurement stations made global and affordable

What is a virtual station?

A virtual station is located at the crossing of satellite tracks (500km intertracks with 2 satellites, 300km intertracks with 10 satellites) and freshwater bodies. It will measure the water height of the exact same water body on a daily basis.

What is the potential number of virtual stations?

Up to 50.000 virtual stations will provide global daily water level measurement data with a constellation of 10 nanosatellites.

Long term, BWI wants to reach the number of 80 nanosatellites in orbit to maximize global geographic coverage.

BWI constellation economic advantage

Ground measurement stations cost approximately 5.000€ per year (incl. installation & maintenance). One virtual measurement station (acquired by a space sensor) costs approximately 250€ per year (excl. downstream hosting, sales & marketing costs), assuming a global network of 30.000 virtual stations. The BWI constellation will divide existing freshwater height monitoring costs by a factor of 20!

Climate change

An eagerly awaited climate resilience space infrastructure

Climate change

Twice a day revisit of a hydrological basin

NRT snapshot of water surface elevations for all the basin (70 min for Congo basin).

Scale on-demand

Every 24 hours for ascending and descending tracks (separated by ~12 hours).

A tool for science, for policy-making, and for business

The BWI constellation will provide inland water height data for free to the scientific community, and the data will be made available after subscription to governments and businesses.

Interested in daily updated inland water level data?

Get in touch

A basin digitization enabler, BWI specializes in the monitoring and forecasting of inland surface water reserves around the globe. BWI brings together in-situ data, spaceborne observations and machine learning to feed and empower hydrological and hydrodynamical models. A provider of online subscription-based virtual continental freshwater monitoring stations, BWI aims to make scalable – across space and time – hydrological software to address climate change induced water stress. BWI also strives to launch a constellation of 10 smallsats equipped with miniaturized altimeters to monitor inland water levels globally.

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