Clark University - Clark News Fall 2002
High Above Hawaii (fall 2002)
Professor Stanley Herwitz is bringing aerial technology down to earth
Clark physicist Robert Goddard developed the technology that eventually put man on the moon. Three-quarters of a century later, Clark Professor Stanley Herwitz is working to apply space-age technology to earth-bound challenges.
Herwitz, professor of biogeography and earth science, is leading a team of researchers at the National Aeronautics and Space Administration's (NASA) Ames Research Center on a mission exploring, with great success, the commercial uses of Unmanned Aerial Vehicles (UAVs) equipped with digital cameras. Specifically, Herwitz is examining how digital images taken from a solar-powered UAV can assist farmers on large plantations determine the best time to harvest their crops.
Herwitz's research is supported by a NASA grant totaling $3.76 million—the largest grant ever awarded to a Clark faculty member. In addition, Clark and NASA signed a Memorandum of Understanding last spring, leading to the establishment of a UAV Applications Center in the new NASA Research Park in California's Silicon Valley.
Harvesting the best coffee
Herwitz has been studying the earth from an aerial perspective for more than 20 years, focusing mainly on tropical rainforest vegetation and the health of tropical rainforest tree canopies. In 1997 and 1998, Herwitz served as a science team member with NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. When ERAST needed a site for UAV test flights and image collection, Herwitz suggested the Kauai Coffee Company, the largest coffee plantation in the United States.
"Then I became interested in how UAVs could be used for airborne imaging," says Herwitz, who was able to identify areas of disease and irrigation problems in the images collected by the ERAST program. In discussing the project with managers at the Kauai Coffee Company, he also discovered the company's need to locate the ripest coffee fields during the harvest season. That got Herwitz thinking about how digital images taken from a UAV could be used to help the company target its harvest.
"Determining the location of the ripest coffee fields is no easy task," Herwitz says, especially now that large plantations like Kauai Coffee Company are using mechanical harvesters that collect all coffee cherries—ripe or not—in a given field. "Our research will set the stage for other UAV applications requiring timely high-resolution imagery well into the future."
The latest mission
In September and October, Herwitz and his team conducted two demonstration flights over the Kauai Coffee Company plantation using Pathfinder-Plus, a high-flying, solar-powered UAV. The Pathfinder-Plus loitered for several hours over the plantation, while digital cameras strapped to the aircraft collected color and infrared images of the fields. The experimental flights succeeded, Herwitz says, "beyond our wildest dreams."
"We've accomplished our goals on a level that we only dreamed about," Herwitz says. "We were able to deal with 80 percent cloud cover, loiter for four hours and assemble a mosaic of clear-sky images that provided a cloud-free view of the entire plantation."
The images were transmitted wirelessly to the research station on the ground, where they were processed, analyzed and given to the harvest managers, who were then able to dispatch the mechanical harvesters to the ripest coffee fields.
Herwitz hopes to refine the system so that harvest managers can receive near real-time images of the fields and determine, down to the day, the best time to harvest. This technology is valuable not only for harvesting coffee, but for any situation that requires timely image acquisition. Forest-fire management and disaster monitoring are some of the other time-sensitive applications that could benefit from future flights, he says.
While observing the earth from the air is nothing new, researchers like Herwitz are discovering the distinct advantages of UAVs. They don't require a pilot or fuel, which saves money. And unlike planes and satellites, UAVs travel slowly for extended periods of time, which means they can loiter over an area of interest awaiting clear skies. This is especially important in Hawaii, Herwitz says, where low, puffy cumulous clouds often develop throughout the day.
Beyond agriculture
Because of these advantages, Herwitz envisions many other uses for UAVs.
"The ability to put an imaging system on this type of plane means it can be used for other functions such as disaster relief, fire management, homeland security and any situation where you need imagery in near real time," he says.
In the case of a forest fire, for example, Herwitz says a UAV equipped with a thermal sensor can essentially see through the smoke to identify the hottest areas.
"You're really mapping heat, which is the area of concern."
At a disaster site, a UAV could help emergency management teams locate areas that incurred the most damage. Since Sept. 11, Herwitz adds, the military has also shown a keen interest in UAVs and how they can be used for reconnaissance.
A challenging endeavor
For Herwitz, managing the mission has been as much a learning experience as the research itself. Most challenging, he says, is shouldering the responsibility for the entire mission.
As principal investigator, Herwitz manages a team of more than 20 researchers, defining tasks and goals while controlling costs. He submits monthly reports to NASA, negotiates contracts, manages the budget and sets the schedule. One of the biggest challenges, Herwitz adds, is making sure the digital cameras are functioning before the UAV takes off.
"Once the plane is up, it doesn't land until nightfall," he says. If the camera malfunctions, the flight is wasted. "So, there's both stress and excitement."
From Hawaii to Clark
Incorporating classroom learning is also an important aspect of the project for Herwitz, and he considers the establishment of a NASA-Clark UAV Applications Center an important milestone for the University.
"It gives Clark a presence in the NASA research park," Herwitz says, as well as a base for a leading-edge educational program. Herwitz taught a graduate course on digital-image analysis last fall, with students helping to analyze more than 1,000 images of the Kauai Coffee Company plantation. "They participated in the project, and their participation was an important contribution."
A graduate student from the course joined the project in California and Hawaii for the October demonstration flights, and Herwitz plans to bring more graduate students to work on site in the future. He will also conduct a Clark course from the UAV Applications Center using video conferencing.
"Our center sets the stage for future educational programs for Clark, as well as a base for future UAV missions," Herwitz says.
Professor Stanley Herwitz's research into commercial applications for UAVs is capturing the attention of media outlets throughout the country and around the world. The latest coverage of Herwitz's research is available on the Clark Web site, www.clarku.edu/faculty/herwitz.
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Field Harvesters