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 University of Colorado Boulder’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.  

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.”