RF and microwaves

Open-source coding platform makes radar technology accessible to scientists worldwide

Charles Ferrer — Mon, 14 Sep 2026 15:55:58 +0000

Open-source coding platform makes radar technology accessible to scientists worldwide Charles Ferrer Mon, 09/14/2026 - 09:55

Members of the Hi-SNR Lab who helped develop the Open Radar Code Architecture initiative, an open-source software framework built specifically for environmental monitoring.

Charles Ferrer

Radar technology is one of the most powerful tools to better understand our world around us.

Researchers use radar to see beneath the surface of ice, forest canopy or soil in ways the human eye never could. As the planet changes, that kind of capability matters more than ever.

Undergraduate researcher, Colin Chow (left), discussing results of radar testing with Assistant Professor Nicole Bienert.

But for the researchers who actually build these tools, there’s a frustrating dilemma: Before a radar system can answer a scientific question, someone has to spend months, oftentimes much longer, building the radar and writing code just to get it operating.

It’s a rite of passage familiar to nearly all in the radar research community. A new student joins a lab, inherits a software-defined radio and starts writing the same kind of control code to make it operate as a radar.

A team at the �Ǹ�Թ�’s High precision Imaging, Signals ‘N Radar (Hi-SNR) Laboratory is working to change that.

The lab, based in the Department of Electrical, Computer & Energy Engineering is leading the Open Radar Code Architecture (ORCA) initiative, an open-source software framework that turns commercially available software-defined radios (SRD) into functioning radar systems built specifically for environmental monitoring.

“It takes a student a year to get to this base level of radar operation,” said Nicole Bienert, assistant professor of electrical engineering. “Every new student is just recreating the wheel over and over. That’s not an efficient use of our time as researchers if we really want to answer major scientific questions."

ORCA is designed to close that gap. Rather than every research group re-writing radar-control code from scratch, ORCA gives them a starting point they can build on, so more radar research questions can get answered.

From ice to trees

The project traces its roots to Bienert’s doctoral research in the Stanford Radio Glaciology group and the team she worked with, which included Thomas Teisberg and Anna Broome. ORCA was initially introduced by those researchers for studying the cryosphere, with Teisberg developing a fixed-wing drone system for measuring glacier ice thickness and Broome developing a multi-frequency radar system.

ORCA can be applied in important ways that measure environmental change.

Soil moisture monitoring for agriculture uses.

Snow levels for avalanche warning.

Snow water equivalent for water resource management.

Tree water content for wildfire risk.

Glacier material analysis for sea level rise.

Contribute to and connect with ORCA

Since its introduction in 2024, the code and instruction sets have expanded, and the use cases have extended beyond cryospheric research. The community has grown through monthly meetings and online forums with participants from multiple universities in different continents.

Christopher Barbarie, a PhD student in ECEE, is developing radar systems and algorithms to determine material and roughness conditions at the base of ice sheets in the Arctic.

Zoe Worrall, also an ECEE PhD student, is applying the same underlying foundation to an entirely different realm by developing a hardware system to determine water content within trees.

“Anybody who has a science question that can be answered with radar can and should use this open code architecture,” Barbarie said. “There’s no point in reinventing the wheel since the code’s already there.”

When Barbarie and Worrall’s cohort inherited ORCA, the code base worked, but it wasn’t built for a specific audience. There was little documentation, the code was difficult to read and there were no automated tests to confirm that changes hadn’t broken anything.

Over the past year, with help from undergraduate researchers mentored by Barbarie and Worrall, the lab rewrote most of the code base, added unit tests and restructured it so new functionality can be added.

“The undergrads did an amazing job last summer,” Worrall said. “They took the code base and made it not only usable, but readable and able to be updated in a way that multiple people could come in on the project.”

Their hope is that more researchers can adopt ORCA regardless of which hardware they already own. ORCA was built for any environmental radar project can adapt, whether the goal is ice-penetrating radar, multi-frequency sensing or something researchers haven’t explored yet.

What it takes to build a radar

Part of ORCA’s appeal is just how far radar hardware has come. A radar system that once cost upward of several hundreds of thousands of dollars can now be assembled from a software-defined radio priced in the low thousands of dollars, paired with off-the-shelf antennas and cables.

Members of the Hi-SNR Lab who helped develop the Open Radar Code Architecture initiative, an open-source software framework built specifically for environmental monitoring.

“You buy some antennas, some cables, the SDR, download the code, follow the instructions and now you have a radar,” Bienert said. “We’re trying to get to a point where scientists can do that on their own and they don’t need a bunch of radar background.”

Accessibility matters because the people asking environmental questions aren’t always the people trained to build radar hardware from scratch.

A geophysicist studying ice sheets, an ecologist studying water movement in trees or an engineer developing a new sensing method for distributed radar arrays, tomography or multi-sensor data fusion — none of them need to become a radar engineer first.

“A lot of times in the geophysics community, you have the science question you want to answer, and you might not have the technical background to be developing code structure or hardware,” Barbarie said. “Someone without a coding background can use ORCA since it’s basically plug and play with your system, so you don't have to worry much about the technical side of things."

Researchers can submit their own code through GitHub for review before it’s merged into the broader ORCA architecture, the same collaborative model that powers much of the open-source software world.

If researchers are spending less time rebuilding infrastructure, they can spend more time answering questions like how fast a glacier is melting, how much water a tree is holding or a question no one has thought to ask yet.

“We encourage people to be actively contributing,” Worrall said, “and if people want more help getting started or want to be more involved, they should reach out to us. We’d love to grow the community.”

A team at the High precision Imaging, Signals ‘N Radar Lab at CU �Ǹ�Թ� is leading the Open Radar Code Architecture (ORCA) initiative, an open-source software framework that turns commercially available software-defined radios built specifically for environmental monitoring.

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Hi-SNR lab students working on code base and conducting tests to verify functionality. Photo Credit: Jesse Petersen

Draper Scholar to explore 3D-printed lens design

Charles Ferrer — Tue, 01 Jul 2025 19:47:59 +0000

Draper Scholar to explore 3D-printed lens design Charles Ferrer Tue, 07/01/2025 - 13:47

Charles Ferrer

Samuel Silberman, an incoming PhD student in electrical engineering, has been named a 2025 Draper Scholar by Draper. The prestigious graduate fellowship will support his research into radio frequency (RF) lens design using advanced 3D printing and additive manufacturing.

“My Draper fellowship will focus on developing synthesis and optimization methods for the design of RF lenses,” Silberman said. “These lenses will leverage multi-material additive manufacturing and corresponding material parameters achievable through advanced 3D printing techniques.”

RF lenses are critical components in communication and radar systems, often used to create highly directional lens antennas. Through his fellowship, Silberman hopes to take advantage of innovative 3D printing capabilities to improve the performance of these devices.

The Draper Scholar Program provides five years of funding and offers scholars access to scientists and engineers at Draper in Cambridge, Massachusetts. In addition to virtual mentorship, he will travel to Draper annually to present his research and connect with other fellows across the country.

Last summer, Silberman participated in undergraduate research through Canada’s Natural Sciences and Engineering Research Council program. He worked on a resonant capacitive power transfer system for electrified roadways, conducting electromagnetic analysis and designing power electronics for the system. That hands-on experience cemented his interest in RF systems and power transfer and ultimately influenced his decision to pursue his PhD at CU �Ǹ�Թ�.

“I was drawn to the work being done in electromagnetic metamaterials by my advisor, Cody Scarborough,” Silberman said, “and Colorado’s great skiing and hiking scene was an added bonus.”

He will be co-advised by Rob MacCurdy, assistant professor of mechanical engineering, on the mechanical aspects of the project.

Silberman earned his bachelor’s degree in electrical and computer engineering from the University of New Brunswick in Fredericton, Canada.

“I’m really excited to contribute to the field and grow as a researcher through this opportunity,” he said.

Samuel Silberman, an incoming PhD student in electrical engineering, has been named a 2025 Draper Scholar by Draper. The prestigious graduate fellowship will support his research into radio frequency lens design using advanced 3D printing and additive manufacturing.

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Al Gasiewski presented IEEE award for remote sensing research

Anonymous — Tue, 07 May 2024 14:48:38 +0000

Al Gasiewski presented IEEE award for remote sensing research Anonymous (not verified) Tue, 05/07/2024 - 08:48

Charles Ferrer

Professor Al Gasiewski was presented the Golden Florin award from the IEEE in recognition for his more than 40 years of outstanding contributions in passive microwave remote sensing research.

“I am grateful to the dozens of colleagues, advisors and students who throughout the past decades have made the progress in environmental remote sensing possible,” said Gasiewski, “and my family has been a constant source of support in my endeavors to better protect our planet.”

Based in the Department of Electrical, Computer and Energy Engineering at CU �Ǹ�Թ�, Gasiewski has been a CU �Ǹ�Թ� faculty member since 2006. He is the founding director of the Center for Environmental Technology, a laboratory which develops innovative observing systems for environmental applications.

Environmental research for global future

“It is more important than ever that we strive to take care of our environment and maintain professional opportunities for individuals globally to study remote sensing science,” said Gasiewski.

He added that his research provides a unique means of observing the large-scale environment of the planet.

“Microwave remote sensing provides us critical data about the atmosphere, oceans, ice sheets, land masses from forests to cities and numerous other related environmental realms,” he said. “It permits us to make informed decisions from the individual to the societal level that best protect our shared future.”

Gasiewski’s research has focused on sensing the natural environment using microwaves. He has developed a variety of microwave radiometers for weather and climate monitoring, including polarimetric radiometers used for ocean wind sensing, millimeter and submillimeter wave radiometers for measuring atmospheric temperature, water vapor, clouds, precipitation, imaging radiometers for sea ice and soil moisture mapping.

He recently developed a new radio detection method that promises to provide precise microwave measurements from weather satellites amidst the increasing amount of radio noise from wireless communications systems. His work is foundational to our system for global weather forecasting using satellites.

Gasiewski is an IEEE Fellow and member of the American Meteorological Society, American Geophysical Union and the International Union of Radio Scientists. His past awards include the IEEE GRSS' Education award in 2017 and the IEEE GRSS’ Outstanding Service Award in 2006.

�Ǹ�Թ� the Golden Florin Award
The Golden Florin Award is jointly sponsored by the IEEE Geoscience and Remote Sensing Society (GRSS) and the Italian Centre for Microwave Remote Sensing. Recipients are national and international members of the GRSS. The Golden Florin is awarded every two years to researchers who have distinguished achievements and scientific breakthroughs in microwave radiometry in remote sensing.

Photo: Al Gasiewski awarded the 2024 Golden Florin award by the IEEE GRSS and the Italian Centre for Microwave Remote Sensing.

Professor Al Gasiewski was presented the Golden Florin award from the IEEE in recognition for his more than 40 years of outstanding contributions in passive microwave remote sensing research.

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PhD candidate wins CU �Ǹ�Թ� Three Minute Thesis competition

Anonymous — Tue, 11 Apr 2023 20:22:27 +0000

PhD candidate wins CU �Ǹ�Թ� Three Minute Thesis competition Anonymous (not verified) Tue, 04/11/2023 - 14:22

Emily Adams

Even as an undergraduate, Rob Streeter was aware of the communication gap between scientists and the general public.

“On one of the very first publications I submitted for review, I got back a comment that said, ‘You’re supposed to be an expert. Why don’t you write like one?’” said Streeter, now a PhD candidate in Distinguished Professor Zoya Popovic’s Microwave and RF Research Group. “And I thought, ‘Your feedback is irrelevant. I’m not trying to be exclusive. I’m intentionally trying to write in a way that more people can understand.’”

When he heard about the Three Minute Thesis contest, he knew he wanted to be a part of it. The annual competition challenges PhD students to describe their research in three minutes, with just one PowerPoint slide, to a general audience.

Streeter won the CU �Ǹ�Թ� competition with his presentation, “A New Way to Measure Internal Body Temperature.” He also went on to earn an honorable mention at the Western Association of Graduate Schools Conference in Portland, Oregon.

Even with a commitment to clear communication, Streeter said it was still challenging to step back from his research project, in which they are trying to measure the temperature of an internal tissue layer — the brain, for instance — passively and non-invasively. His latest conference publication was titled “Near-field Thermal Radiation Reception Spatial Sensitivity Mapping at 1.4 GHz” — not exactly intended for the layperson.

“I had to think about, in essence, what are we creating?” he said. “Well, we’re creating a thermometer. Everyone knows what a thermometer is.”

From there, the competition’s workshops, trainings and improv sessions helped him hone why people should care about that better thermometer.

During his presentation, he talked about an emergency heart surgery in which doctors have to cool the body, making it important to monitor brain temperature. Currently, the gold standard for monitoring brain temperature involves inserting a catheter in the nose.

“So, obviously, that’s uncomfortable,” Streeter said. “Plus, it’s a separate surgery, it takes a while to converge on a stable temperature, and you’ve got a limited amount of time for the surgery. So you’ve got something that takes a long time, and you’ve got a narrow time window.”

Even once he got to that explanation, it still took a lot of back and forth with people outside his field to make the presentation as simple as possible.

“It's really fascinating to me what parts of what you choose to say people will get hung up on. I think I'm saying something that totally makes sense, and the judges ask about some word that I never even thought about,” Streeter said. “It's neat to learn how to be a better communicator in that way where every word you choose is important.”

After he graduates in May, Streeter is headed to central Greenland, where he’ll be the site supervisor on a research station. He looks forward to using some of the leadership experience he has gained at CU, in addition to skills he learned during a previous research deployment in Antarctica.

And he’s done his best to pass along the importance of science communication skills to others in his lab.

“An example that I've used for years with my two mentees is that you may have the best, irrefutable, mathematically proven solution to a problem,” Streeter said. “But if you can't communicate that solution to your supervisor, to the rest of your team, to your investors, to the people you're going to try to sell that idea or product to — if you can’t explain it and make it so crystal clear to them that it is the best solution, nobody cares.”

Rob Streeter won the CU �Ǹ�Թ� Graduate School's competition with his presentation, “A New Way to Measure Internal Body Temperature.”

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Distinguished professor receives honorary doctorate from Spanish university

Anonymous — Mon, 11 Jul 2022 23:09:11 +0000

Distinguished professor receives honorary doctorate from Spanish university Anonymous (not verified) Mon, 07/11/2022 - 17:09

Distinguished Professor Zoya Popovic was recognized recently with a Doctor Honoris Causa by Universidad Carlos III de Madrid, where she held a Chair of Excellence position during the 2018-19 academic year. In a video interview, she discussed applications of her research in medicine and wireless power and the importance of role models for women in engineering.

[video:https://youtu.be/Ow6Wkmtno1w]

Zoya Popovic previously held a Chair of Excellence at Universidad Carlos III de Madrid.

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PhD student receives competitive Department of Defense fellowship

Anonymous — Mon, 11 Jul 2022 15:53:46 +0000

PhD student receives competitive Department of Defense fellowship Anonymous (not verified) Mon, 07/11/2022 - 09:53

Electrical engineering PhD student Michelle Pirrone has won a prestigious Department of Defense fellowship for her promising research in microwave engineering and machine learning.

National Defense Science and Engineering Graduate (NDSEG) Fellowships provide three years of funding for tuition and fees, as well as a monthly stipend and travel budget. The DoD awards approximately 500 fellowships each year to students across the country.

We asked Pirrone to share some thoughts on her journey in electrical engineering and advice for those considering a PhD path.

How did you originally choose to study electrical engineering?

I originally started as a mechanical engineering major in my undergrad but had an electrical engineering professor recruit me for research on antennas and 3D printing. I thought it would be a good opportunity to try something new, so I gave it a shot and loved working on microwaves engineering so much that I switched majors and decided to continue with the work in my PhD.

What made you decide to pursue your PhD at CU �Ǹ�Թ�?

After working on the antenna research in undergrad, I felt that I had only just scratched the surface with microwaves engineering and really wanted to learn more and try to solve many of the questions or problems I had encountered in my original research. When I came to CU �Ǹ�Թ� for visit week, it was my first time in Colorado, and I fell in love with the region. Both the professors and the students in the microwaves program were very welcoming and worked well together, which was a camaraderie that I had not seen at any other program. I decided then to take the leap, not only with going for a PhD, but also moving across the country to Colorado.

Tell us about the project you’re working on now. What do you find most interesting or satisfying about the work?

I am currently working on integrating machine learning techniques into microwaves systems that change in real time. As the requirements for things like communication systems and reconfigurable networks continue to increase, we are hoping to address these demands by allowing machine learning techniques to dynamically improve system performance as operating conditions vary. I originally started the PhD program working solely on microwave design, but I love the challenge of having to work on two very technical and different topics as microwaves engineering and machine learning are. Not many people have tried to put these topics together before like we are doing, and the projects are forcing me to take new approaches to problems in totally different ways than I would never have had to before.

What is your favorite part about working with your faculty co-advisors, Taylor Barton and Emiliano Dall’Anese?

Both of my advisors have been really great about being open-minded and giving me the room to make some of my own decisions and choices as we work on projects. However, I also always feel like they are there for me when I need support or am stuck on a part of my research and don't know how to continue. I believe we have struck up a really good balance of independence and mentorship, and the three of us work very well on capitalizing on each other's strengths for the research.

What’s next after you finish your PhD?

I still have a few years to go before finishing my PhD, and I like to always keep my opportunities open until it's time to make the final decision. I think I am currently considering going into industry to get some new experience after spending several years in the academic sphere, but only time will tell.

What advice would you give students considering pursuing their PhD?

For most of my time in undergrad, getting a PhD was not on my radar. It wasn't until I found a topic of interest that I really enjoyed that I started to seriously consider graduate school. And even though I work on totally different topics than I did in my undergrad research, there has always been a level of engagement with my work in which I always had been asking questions on if something was possible or how something worked, and now I could actually answer these questions that no one had before. Getting a PhD requires always trying to solve problems or innovate, and I think anyone considering getting a PhD needs to ask themselves if they will enjoy both the frustrations and the satisfaction that comes with forging their own path forward on things no one has really done before.

Do you have any hobbies you’d like to share?

As probably a large portion of Colorado shares, I love being outdoors and in particular love hiking. It's amazing to me how many beautiful hikes are such a short drive away from this area, and I really like doing long hikes that get you far away from the typical hustle bustle of our everyday lives. In addition to that, I really like to cook and try to make foods I've tried at restaurants at home and also like to weight lift.

Anything else you want readers to know about you or your work?

I really didn't expect to be where I am in my life right now or working on what I do, but I took some chances on trying new things along the way, and I'm hoping to continue to push the limits in my research of what's out there now and what we can accomplish.

Michelle Pirrone has won a prestigious National Defense Science and Engineering Graduate (NDSEG) Fellowship for her promising research in microwave engineering and machine learning.

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Popovic elected to National Academy of Engineering

Anonymous — Tue, 01 Mar 2022 16:55:46 +0000

Popovic elected to National Academy of Engineering Anonymous (not verified) Tue, 03/01/2022 - 09:55

Emily Adams

Popovic (bottom left) and several of her graduate students in their lab.

Distinguished Professor Zoya Popovic has been elected to the National Academy of Engineering, one of the highest professional distinctions granted to engineers in academia and industry.

Popovic was honored “for developing high-efficiency microwave transmitters and active antenna arrays for wireless communication systems and for engineering education,” according to a press release from the NAE.

While Popovic said it’s a big honor for her personally and professionally, her thoughts quickly turned to how it will benefit her graduate students, both current and alumni.

“It is good for my students and will help them make more connections,” she said.

Popovic added that she hopes they seat her by fellow 2022 NAE inductee Elon Musk at the award ceremony.

“People like him who are on the industry development side need our students – all of his companies need RF engineers,” she said. “I’m hoping to ask him to endow some student fellowships at CU.”

As an educator, Popovic has graduated more than 65 PhD students, with 16 more working on their graduate degrees in her lab today. She has also developed five undergraduate and graduate electromagnetics and microwave laboratory courses, in addition to co-authoring the textbook Introductory Electromagnetics with her late father.

“Zoya is deeply committed to the educational experiences of both the students in her courses and the substantial number of graduate students that she has supervised in her career,” said Chris Myers, chair of the Department of Electrical, Computer and Energy Engineering. “Her leadership has established an internationally renowned center for RF research and education.”

Popovic’s research interests are in high-efficiency power amplifiers and transmitters, microwave and millimeter-wave high-performance circuits for communications and radar, medical applications of microwaves, quantum sensing and metrology, and wireless powering.

She is a fellow of the IEEE and the recipient of two IEEE MTT Microwave Prizes for best journal papers. She is also a winner of the White House NSF Presidential Faculty Fellow award, the URSI Issac Koga Gold Medal, the ASEE/HP Terman Medal, and the German Alexander von Humboldt Research Award. She was elected as foreign member of the Serbian Academy of Sciences and Arts in 2006 and was a Chair of Excellence at the Carlos III University of Madrid, Spain, in 2019.

Popovic has been a faculty member at CU �Ǹ�Թ� since 1990. She was named a distinguished professor – the highest honor the university bestows on faculty members – in 2010. In 2017, she also became the first faculty member to hold the Lockheed Martin Chair in RF Engineering.

Popovic is serving on several working groups for SpectrumX, a $25 million research center to transform the landscape of radio frequency spectrum research, education, collaboration and management. In 2020, she was among the winners of CU �Ǹ�Թ�’s Lab Venture Challenge for a novel core body temperature sensor her group developed, now commercialized as LumenAstra with Popovic as chief science officer. She has received significant research funding from the U.S. Navy (ONR, NRL and Crane), the Defense Advanced Research Projects Agency and Lockheed Martin, as well as continuous support from the National Science Foundation.

College of Engineering and Applied Science Acting Dean Keith Molenaar said the NAE election is fitting for such an impactful career, noting the many recognitions Popovic has earned in her career.

“She is undoubtedly one of our most highly recognized professors by our scholarly peers, both nationally and internationally,” Molenaar said. “However, when I describe Professor Popovic to a new student, faculty member or alumni, I always start by talking about her excellence as a teacher and mentor. She is truly invested in both research excellence and the success of each one of her students.”

Popovic and fellow CU Engineering honoree Brian Argrow will be officially inducted into the NAE during the organization’s annual meeting in Washington, D.C., on Oct. 2.

Distinguished professor honored “for developing high-efficiency microwave transmitters and active antenna arrays for wireless communication systems and for engineering education.”

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