Honeywell Helps SWOT Team Study Earth’s Water from Space

Water is the most abundant substance on Earth. It covers about 71% of the planet, constitutes up to 60% of the human body and is essential to all forms of life. No wonder scientists are making it a priority to study the world’s surface water, how it changes and circulates over time, and how global warming affects our oceans, lakes, rivers, reservoirs and coastlines.

Scientists are getting ready to take the closest look ever at the world’s surface water with the new SUV-sized SWOT satellite, which is scheduled to launch Dec. 12, 2022, from Vandenberg AFB, California. SWOT – which stands for Surface Water and Ocean Topography – will make the first global survey of Earth’s surface water.

SWOT is being jointly developed by NASA and France’s Centre National D'Etudes Spatiales (CNES) with contributions from the Canadian Space Agency (CSA) and United Kingdom Space Agency.

From an initial orbit more than 530 miles (853 kilometers) above the Earth, SWOT instruments will be able to survey at least 90% of the world’s surface water and take measurements 10-times more accurate than any previous Earth-observation satellite. 

Honeywell Technology Delivers Extreme Accuracy

Thanks partly to technology from Honeywell’s space systems unit, instruments on the SWOT satellite are so precise they can measure water surface height within 2 centimeters, which is about the width of a U.S. nickel, according to Craig Molford, Honeywell’s Senior Director of Space Payload Products. 

The spacecraft will collect data over two swaths of the Earth’s surface at time, each of hem 30 miles (50 kilometers) wide and located on either side of the satellite. RF returns from the surface will be triangulated and used to measure the height of the water’s surface at unprecedented levels of accuracy.

The Honeywell RF duplexer is part of the radio frequency subsystem produced by Thales Alena Space. It performs the switching and routing essential to the instrument’s ability to manage transmit, receive and calibration signals, Molford explained. “We used sophisticated ferrite switches to enable bi-directional communications over one channel. The RF duplexer makes sure the signals route properly to and from the antennas and essentially delivers the information necessary for the SWOT satellite to achieve its mission.”

Honeywell Teams Overcome Technical Challenges 

Honeywell engineers began working on the RF duplexer for SWOT in 2015 and delivered the one and only production unit in 2019, after several iterations and a highly disciplined test and validation process. After all, the satellite has a 15-year expected lifespan and Honeywell components need to perform flawlessly under the harshest possible conditions of spaceflight. 

“The SWOT platform duplexer was undoubtedly one of the most challenging and complex RF duplexers ever produced by Honeywell – and we’ve produced a lot of them,” Molford said. “It used an unprecedented number of ferrite switches, couplers and electronics boards to enable the level of performance, accuracy and ruggedness this amazing platform requires.”

Talented Honeywell engineering and manufacturing teams in the UK drew on decades of experience in RF technologies for spacecraft to develop the SWOT duplexer. “It’s less challenging to produce similar RF duplexers for terrestrial use,” Molford pointed out. “But meeting the high requirements of spaceflight requires special knowledge and expertise that very few companies possess.” 

“Honeywell has unique experience and heritage in the space domain that enables us to take on these kinds of challenges and succeed. Above all, we have great teams of people who are dedicated to doing great work for our customers,” he added. “Its exciting to see this project move from inception to launch and to know that technology we worked on will provide scientists with valuable insight about our planet and the effects of global warming.”