Side view image of SWOT satellite from mission overview video. Credit: NASA/JPL-Caltech/CNES/Thales Alenia Space
Research

UMass Amherst Engineering Professor Sees a Decade of Work Culminate with Launch of Revolutionary NASA Satellite

The Surface Water and Ocean Topography (SWOT) spacecraft will provide insights into how the ocean influences climate change; how a warming world affects lakes, rivers, and reservoirs; and how communities can better prepare for disasters, such as floods

As UMass Amherst civil and environmental engineering professor Colin Gleason watched the awesome spectacle of a NASA spacecraft shooting into orbit aboard a Space X rocket, he realized something: Although much of his work over the last decade had all been leading to this exact moment, his hard work was just getting started.

Gleason was among the mission-critical scientists who had worked on the $1.2 billion Surface Water and Ocean Topography (SWOT) spacecraft who gathered at Vandenberg Space Force Base in California in the pre-dawn hours of Dec. 16 to watch the launch. SWOT is a collaboration between NASA and the French space agency Centre National d’Etudes Spatial, with contributions from the Canadian and United Kingdom space agencies.

SWOT uses state-of-the-art radar interferometry technology to measure the height of more than 90% of Earth’s salt and fresh water – including oceans, lakes and rivers. This data will enable hydrologists, ecologists and others to track the location of water over time, which will provide critical information needed to assess water resources on land, track regional sea level changes, monitor coastal processes and observe small-scale ocean currents and eddies.

Gleason has spent nearly his entire professional career working, through one project or another, toward SWOT’s launch.  As a co-lead academic of the Discharge Algorithm Working Group for SWOT, Gleason’s responsibility has been building the software system that can process the many terabytes of river discharge data collected by the satellite into information that is then sent to NASA for public distribution of river discharge, or how much water is actually present in the river at a given time. Helping develop SWOT’s discharge algorithms as project investigator is assistant professor Konstantinos Andreadis, who leads the Computational Hydrology Research Group at UMass Amherst.

“The discharge stuff is brand-new,” Gleason says of the global software engine his team has been building for three years. “The work I’ve been doing for a decade, and that of others, has basically said it should work in theory, but that keeps me up at night.”

As SWOT data will be collected over a 21-day repeating cycle, it can be used to monitor drought conditions and improve flood forecasts, providing essential information to water management agencies, disaster preparedness agencies, universities, civil engineers and others who need to track water in their local areas. SWOT data will also help industries, like shipping, by providing measurements of water levels along rivers, as well as ocean conditions, including tides, currents, and storm surges.

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Colin Gleason
Colin Gleason

However, “SWOT’s real power is in places where we don’t have measurements, or places where there are measurements and they aren’t shared,” Gleason says. For water system managers in regions where this is the case, “SWOT will tell them what others in their basin are doing.

”In addition to the satellite’s software, Gleason is also responsible for the collection of field data from lakes and rivers in a number of locations across the globe as the Lead Academic Scientist for U.S. Inland Waters Calibration and Validation. The data collection sites he will oversee include the Waimakariri River in New Zealand and several rivers in the Arctic Circle. That work will take place over the next nine months. There’s also a French team that has measurement responsibilities for other global lakes and rivers and an ocean team that’s already stationed on ships at sea and conducting SWOT’s ocean measurements.

Conveniently for researchers based at UMass Amherst, the Connecticut River is the world’s longest river to be located under the satellite’s special “validation” scan area in operation for the first few months of the mission’s life.

“There’s almost 400 kilometers of it underneath the orbit,” Gleason says. “It just worked out that way.” Conducting measurements on the Connecticut’s upstream and tidal reaches, from Greenfield to Holyoke, will be a number of graduate and undergraduate UMass Amherst civil and environmental engineering students, as well as professional staff. Comparing the discharge measurements calculated by the satellite with on-the-ground measurements will help assess the accuracy of Gleason’s software.

 

 
Two cameras aboard the Surface Water and Ocean Topography (SWOT) satellite captured the large mast and antenna panels of the spacecraft’s main science instrument deploying over four days, a process that was completed on Dec. 22, 2022. The masts, which unfold from opposite sides of the spacecraft, can be seen extending out from the spacecraft and locking in place, but the cameras stopped short of capturing the antennas at the ends of the masts being fully deployed (a milestone the team confirmed with telemetry data). This video places the two camera views side by side. Credit: NASA/JPL-Caltech/CNES
 

Gleason says one of the “really cool” aspects of the project has been the involvement of a number of UMass Amherst College of Engineering alumni, who also worked on SWOT project by developing its cutting-edge KaRin (Ka-band radar interferometer) instrument. Using instruments like KaRIn, SWOT will revolutionize oceanography by measuring the height of water in the ocean and “seeing” features like currents and eddies that are less than 13 miles across — up to 10 times smaller than those detectable with other sea-level satellites.

UMass Amherst alumni involved include NASA Jet Propulsion Laboratory’s KaRin Instrument Manager Daniel Estaban-Fernandez ’04, radar systems engineer Delwyn Moller ’97, and Dragana Perkovic-Martin ’08, VISAR (Velocity interferometer system for any reflector) instrument manager at JPL, who led testing and aircraft integration of the airborne SWOT instrument, the data from which will be used to help calibrate and validate SWOT data and also to conduct separate science studies.

Shortly after launching into orbit, SWOT successfully made contact with ground stations on Earth and provided early data on the spacecraft’s health. Next SWOT unfurled its KaRin antennae over the course of four days and entered calibration orbit. It is currently in its “engineering checkout” phase before a planned entry into the calibration and validation period in late March 2023.

The Cass River which flows through Frankenmuth, Michigan

In June 2022, Gleason received a NASA grant to work with computer science colleagues at UMass Amherst and the Jet Propulsion Lab in Pasadena, Calif., to create a cloud-based software system providing unprecedented public access to satellite data on Earth’s water quantity and quality.

Artic River student

In Nov. 2021, Gleason and colleague Dongmei Feng, a civil and environmental engineering researcher, assimilated satellite information into on-site river measurements and hydrologic models to calculate the past 35 years of river discharge in the pan-Arctic region.