How Remote Sensing Technologies Increase Food Production

You might be able to take the girl off the farm, but you can’t necessarily take the farm out of the girl, as the saying goes.

That was the case for Melba Crawford, who as a teenager couldn’t wait to leave her family’s farm in Illinois to pursue an engineering career.

MELBA M. CRAWFORD

EMPLOYER

Purdue University, West Lafayette, Ind.

TITLE

Professor of civil engineering, agronomy, and electrical and computer engineering

MEMBER GRADE

Fellow

ALMA MATERS

University of Illinois, Urbana-Champaign

Ohio State University, Columbus

But her engineering path eventually led her back to agriculture. She has developed remote sensing technologies that, among other uses, map crops more accurately, increase crop yields, and improve management practices while reducing the time it takes to select promising new hybrids.

Crawford is a professor of civil engineering, agronomy, and electrical and computer engineering at Purdue University, in West Lafayette, Ind. In agronomy, she collaborates with researchers in plant genetics, plant physiology, agrometeorology, and soil science. In engineering, she focuses on developing methods to analyze remote sensing data.

For her “contributions to remote sensing technology and leadership in its application for the benefit of humanity,” the IEEE Fellow is the recipient of this year’s IEEE Mildred Dresselhaus Medal. The award is sponsored by Google.

An early environmental activist

As a teen in the 1960s, Crawford was drawn to the U.S. space program; she initially aimed for a career in the aerospace industry.

“Space was really inspiring in those days,” she says. “I did not want to be an astronaut, because I’m claustrophobic. I was interested in the design and operation of airplanes and spacecraft.”

But during her time as a freshman at the University of Illinois in Urbana-Champaign, the aerospace industry went through a period of mass layoffs. She realized that aerospace was a boom-and-bust industry, she says.

Meanwhile, she says, environmental issues were gaining attention as the impact of acid rain and contamination of lakes and rivers became better understood.

“People were really interested in clean air and clean water, so I decided there would always be interest in the environment,” Crawford says. She switched her major to civil and environmental engineering.

“You study many areas in civil engineering, including structures, soils, transportation, and the environment,” she says. After graduating in 1970, she stayed on at the university to earn a master’s degree in civil engineering in 1973, focusing on environmental engineering.

She then pursued a Ph.D. in systems engineering at Ohio State University, in Columbus. Her research there focused on model-based system approaches and mathematics.

When it came time to find a topic for her dissertation, she learned that the U.S. Environmental Protection Agency, in implementing the 1970 Clean Air Act, was struggling to establish baselines for air-quality levels, she says.

“To utilize these regulations, you first must establish where you currently are with air-quality levels,” she says. Her dissertation focused on developing methods to determine a baseline for concentrations of pollutants in the atmosphere based on historical spatial-temporal measurements. She earned her Ph.D. in 1981.

She had planned to become a consultant for an environmentally related organization, but during her last year at Ohio State a faculty member became ill, and the department asked her to teach one of his classes.

“That’s how my career took a turn toward academia,” she says.

Remote sensing technologies to tackle earth science problems

In 1980 Crawford joined the mechanical engineering department at the University of Texas at Austin, staying for 25 years. As a member of the industrial engineering and operations research group, she developed advanced methods for image analysis and applications for mapping and monitoring land cover using satellite imagery.

She also founded an interdisciplinary research and applications development program in space-based and airborne remote sensing at UT. As part of that effort, she installed and operated a receiving station to acquire and analyze data from the U.S. National Oceanic and Atmospheric Administration’s satellites over extended areas of North America and the Gulf of Mexico.

Her team’s research program included projects in Australia and Africa. The team also developed new algorithms for analysis of hyperspectral imagery, which provides detailed information across the electromagnetic spectrum to detect chemistry-based changes in vegetation.

Agriculture didn’t come back on her radar until 2006, when she joined the Purdue faculty. The university already had a 30-year history of collaboration between the colleges of engineering and agriculture in using remote sensing to address problems in agriculture such as detection and mapping disease in crops. Researchers originally used aerial photography, then satellite images. Through the university’s Laboratory for Applications of Remote Sensing, the colleges had developed international collaborations in advancing analysis of remote sensing data and developing open-source software for applications and education.

“People were really interested in clean air and clean water, so I decided there would always be interest in the environment.”

“When I told my family that Purdue had recruited me, my father asked whether the school understood that I didn’t know much about agriculture,” she says, laughing. “Purdue was interested in my work in remote sensing and data analytics. These technologies provide capability to acquire data frequently over extended spatial areas—which is critical for agriculture.”

Her work is currently contributing to developing improved strategies for applications of nutrients and herbicides to crops. Through her contributions to plant breeding, she is helping improve the security and resilience of food production internationally.

Crawford recently helped lead a project funded by the U.S. Department of Energy to develop unmanned aerial vehicle platforms and algorithms to support plant breeders in developing sorghum hybrids for biofuels—potential substitutes for corn-based ethanol.

Beyond academia, Crawford advised NASA as a member of the Earth Science Advisory Committee and the advisory board for the NASA Socioeconomic Data and Applications Center.

She was a Jefferson Science Fellow at the U.S. State Department, where she focused on promoting geospatial technologies in developing countries.

In 2001 she realized her goal of working on a satellite mission. She was a member of NASA’s Earth Observing–1 science validation team, which conducted the first successful U.S. civilian hyperspectral mission in space. Although it was designed for a life of 18 months, the mission operated successfully for 16 years. Her research focused on developing new methods to analyze hyperspectral imagery to determine the response of vegetation to natural and man-made hazards.

The legacy of Mildred Dresselhaus

Crawford received the Dresselhaus Medal on 5 May during the IEEE Vision, Innovation, and Challenges Summit and Honors Ceremony, held at the Hilton Atlanta.

Mildred Dresselhaus worked at MIT, which she joined in 1960 as a researcher in its Lincoln Laboratory Solid State Division, in Lexington, Mass. She became a professor of electrical engineering in 1967 and joined the physics department in 1983.

In 2015 Dresselhaus became the first female recipient of the IEEE Medal of Honor. She died in 2017.

Crawford never met Dresselhaus, but she did receive congratulatory messages from several people who knew her.

“The most amazing thing to me has been the emails I received from so many people who knew her but didn’t know me,” Crawford says. “They were former students, colleagues, and friends. They reinforced the perception that Dresselhaus was a truly amazing person as well as a trailblazer.”

One was an MIT electrical engineering student to whom she had given one of her old spectrometers to start his research. Another, who at the time was a junior faculty member at the University of North Carolina in Charlotte, recalled the thoughtful, critical input and encouragement Dresselhaus provided about her research during a visit to the faculty member’s lab.

“One of my colleagues at Purdue, who is a well-known researcher in nanotechnology, was emphatic in his appraisal,” she says. “He asked, ‘Do you realize she was the Queen of Carbon?’ It just made me feel so humble and appreciative.”

You can watch Crawford accept her award on IEEE.tv.

She was also an Innovators Showcase panelist during the summit.

Crawford stresses that her research is interdisciplinary: “My contribution is really in developing algorithms to analyze data, but the purpose is always to address a problem.

“To contribute to the solution, it is necessary to invest in learning about the problem and to work collaboratively with others who are experts in that field.

“Anything that I have accomplished during my career is really the result of a team. I accepted the award on behalf of all of us.”

IEEE: Staying connected to a community

Crawford joined IEEE when she began her academic career and had to publish her research. More than 50 of her papers are in the IEEE Xplore Digital Library.

“Publishing, for many people, is the entry into IEEE,” she says. “Then there is growth in terms of understanding the importance of going to conferences and not only hearing presentations of research but also engaging with people. You start paying attention to what’s going on in a professional society, and you start volunteering. Then you are part of a community.”

Crawford served as 2013 president of the IEEE Geoscience and Remote Sensing Society and was an associate editor of the IEEE Transactions on Geoscience and Remote Sensing. She also has served on several of the society’s administrative committees. Her work was recognized with the GRSS 2020 Outstanding Service Award and its 2021David Landgrebe Award.

Volunteering, she says, is “a two-way street because you contribute to the society but you also benefit in terms of your engagement with individuals and developing leadership skills.”

Being involved provides opportunities, she adds: “People who are quite accomplished in their field attend the meetings, and they’re engaged with the society. You would never, as a junior person, typically have opportunities to meet these people.”

​IEEE Spectrum