Nav: Home

Hyperspectral camera captures wealth of data in an instant

May 20, 2019

Standard snapshots from space don't quite show Earth in all its glory. There's so much more to see.

To reveal details impossible to observe with the naked eye, Rice University engineers are building a portable spectrometer that can be mounted on a small satellite, flown on an airplane or a drone or someday even held in the hand.

Bioengineer Tomasz Tkaczyk and his colleagues at Rice's Brown School of Engineering and Wiess School of Natural Sciences have published the first results from a NASA-funded project to develop a small, sophisticated spectrometer with unusual versatility. Their paper appears in Optics Express.

A spectrometer is an instrument that gathers light from an object or a scene, separates the colors and quantifies them to determine the chemical contents or other characteristics of what it sees.

The Rice device, called the Tunable Light-Guide Image Processing Snapshot Spectrometer (TuLIPSS), will let researchers instantly capture data across the visible and near-infrared spectrum, unlike current systems that scan a scene line-by-line and for later reassembly.

Each pixel in the hyperspectral images produced by TuLIPSS contains either spectral or spatial information. The "pixels" in this case are thousands of optical fibers, flexible light guides that deliver the image components to a detector. Because they can reposition the fibers, researchers can customize the balance of image and spectral data sent to the detector.

The device, for example, can be tuned to measure the chemistry of a tree to see if it's healthy or diseased. It can do the same for a cell, a single leaf, a neighborhood or farm, or a planet. In continuous-capture mode, akin to a camera's motor drive, it can show how the spectral "fingerprints" in a stationary scene change over time, or grab the spectral signature of a lightning bolt in real time.

Tkaczyk said TuLIPSS is unique because it works like any camera, capturing all the hyperspectral data - what researchers refer to as a data cube - in an instant. That means an airplane or orbiting satellite can snap an image of the ground quickly enough to avoid motion blur that would distort the data. Onboard processing will filter the data and send only what's required back to Earth, saving time and energy.

"This would be an interesting tool in the case of an event like Hurricane Harvey," Tkaczyk said. "When there's a flood and potential contamination, a device able to fly over a reservoir could tell if that water is safe for people to drink. It would be more effective than sending someone to a site that may be hard to reach."

In a normal camera, a lens focuses incoming light onto a sensor chip and converts the data into an image. In TuLIPSS, the lens focuses that light onto a middleman: the bundle of optical fibers.

In the current prototype, these fibers collect more than 30,000 spatial samples and 61 spectral channels in the 450-to-750 nanometer range - essentially, hundreds of thousands of data points - split by prisms into their component bands and passed on to a detector. The detector then feeds these data points to software that recombines them into the desired images or spectra.

The fiber array is tightly packed at the input and rearranged into individually addressable rows at the output, with gaps between them to avoid overlap. Spacing the rows allows researchers to tune spatial and spectral sampling for specific applications, Tkaczyk said.

First author Ye Wang, who earned her doctorate this year at Rice, and her colleagues painstakingly built the prototype, assembling and positioning the fiber bundles by hand. They used scenes in and around Rice to test it, reconstructing images of buildings to fine-tune TuLIPSS and taking spectral images of campus trees to "detect" their species. They also successfully analyzed the health of various plants with spectral data alone.

Continuous capture images of moving traffic in Houston showed the system's ability to see which spectra are shifting over time (such as moving vehicles and changing traffic lights) and which are stable (everything else). The experiment was a useful proof-of-concept to show how well the spectrometer could filter motion blur in dynamic situations.

Co-author David Alexander, a professor of physics and astronomy and director of the Rice Space Institute, said the researchers have begun discussions with the city of Houston and Rice's Kinder Institute for Urban Research about testing TuLIPSS in aerial studies of the city.

"Since we need to test TuLIPSS anyway, we want to do something useful," he said, suggesting a hyperspectral map of the city could reveal how the urban landscape is changing, distinguish buildings from parks or map sources of pollen. "In principle, regular flights over the city will allow us to map out the changing conditions and identify areas that need attention."

Tkaczyk suggested future versions of TuLIPSS will be useful for agricultural and atmospheric analysis, algae blooms and other environmental conditions where quick data acquisition will be valuable.

"The real challenge has been to decide what to focus on first," Alexander said. "Ultimately, we want to be successful enough that the next phase of development pushes us closer to flying TuLIPSS in space."
-end-
Co-authors are Rice research scientists Michal Pawlowski, Jason Dwight and Shuna Cheng, postdoctoral researcher Razvan Stoian and graduate student Jiawei Lu. Alexander is a professor of physics and astronomy. Tkaczyk is an associate professor of bioengineering.

Initial funding for the project came through a $2 million, 3-year award to Rice as part of $53 million in grants by NASA's Science Mission Directorate and its Earth Science Technology Office to develop innovative instruments and technologies for future Earth science methods and observations.

Read the abstract at https://www.osapublishing.org/oe/abstract.cfm?uri=oe-27-11-15701&origin=search

This news release can be found online at https://news.rice.edu/2019/05/20/hyperspectral-camera-captures-wealth-of-data-in-an-instant/

Follow Rice News and Media Relations via Twitter @RiceUNews

Related materials:

Rice's spectral eyes bound for the skies: http://news.rice.edu/2016/11/14/rices-spectral-eyes-bound-for-the-skies-2/

Modern Optical Instrumentation and Bio-Imaging Laboratory (Tkaczyk lab): http://www.owlnet.rice.edu/~tt3/

Rice Department of Bioengineering: https://bioengineering.rice.edu

George R. Brown School of Engineering: https://engineering.rice.edu/

Video:

https://youtu.be/kihPhuk60-U

Continuous capture images of moving traffic in the Houston neighborhood around Rice University shows how the TuLIPSS spectrometer filters motion blur in dynamic situations. The full-color video is a composite of the filtered spectral data captured by the device. The portable spectrometer has proven its ability to capture far more data much quicker than other fiber-based systems. (Credit: Modern Optical Instrumentation and Bio-Imaging Laboratory/Rice University)

Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,962 undergraduates and 3,027 graduate students, Rice's undergraduate student-to-faculty ratio is just under 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for lots of race/class interaction and No. 2 for quality of life by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger's Personal Finance.

Rice University

Related Rice Articles:

New rice fights off drought
Scientists at the RIKEN Center for Sustainable Resource Science (CSRS) have developed strains of rice that are resistant to drought in real-world situations.
Domesticated rice goes rogue
We tend to assume that domestication is a one-way street and that, once domesticated, crop plants stay domesticated.
Protecting rice crops at no extra cost
A newly identified genetic mechanism in rice can be utilized to maintain resistance to a devastating disease, without causing the typical tradeoff -- a decrease in grain yield, a new study reports.
Every grain of rice: Ancient rice DNA data provides new view of domestication history
Now, using new data collected samples of ancient, carbonized rice, a team of Japanese and Chinese scientists have successfully determined DNA sequences to make the first comparisons between modern and ancient rice.
Four newly identified genes could improve rice
A Japanese research team have applied a method used in human genetic analysis to rice and rapidly discovered four new genes that are potentially significant for agriculture.
Infants who ate rice, rice products had higher urinary concentrations of arsenic
Although rice and rice products are typical first foods for infants, a new study found that infants who ate rice and rice products had higher urinary arsenic concentrations than those who did not consume any type of rice, according to an article published online by JAMA Pediatrics.
New resource for managing the Mexican rice borer
A new article in the Journal of Integrated Pest Management provides information on the biology and life cycle of the Mexican rice borer (Eoreuma loftini), and offers suggestions about how to manage them.
Fighting rice fungus
Plant scientists are uncovering more clues critical to disarming a fungus that leads to rice blast disease and devastating crop losses.
The origin and spread of 'Emperor's rice'
Black rice was prized in ancient times for its color and is prized in modern times for its high levels of antioxidants, but its early history has been shrouded in mystery until now.
Trigger found for defense to rice disease
Biologists have discovered how the rice plant's immune system is triggered by disease, in a discovery that could boost crop yields and lead to more disease-resistant types of rice.

Related Rice Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Anthropomorphic
Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#532 A Class Conversation
This week we take a look at the sociology of class. What factors create and impact class? How do we try and study it? How does class play out differently in different countries like the US and the UK? How does it impact the political system? We talk with Daniel Laurison, Assistant Professor of Sociology at Swarthmore College and coauthor of the book "The Class Ceiling: Why it Pays to be Privileged", about class and its impacts on people and our systems.