Versions of ground-penetrating radar have been around for nearly a century but, despite advances, the data provided by the technology is still pretty crude. Using cutting-edge hardware and new software powered by artificial intelligence, Haihan Sun is developing ground-penetrating radar systems that can offer incredible amounts of detail.
“I really enjoy this research topic,” says Sun, who joined the University of Wisconsin-Madison in the fall semester 2023 as an assistant professor in electrical and computer engineering. “I find it very useful in helping us better understand the hidden world around us, and I believe it has the potential to promote sustainable engineering.”
Sun received a bachelor’s degree in electronic information engineering from the Beijing University of Posts and Telecommunications before pursuing her PhD at the University of Technology Sydney, in Australia. In 2019, she began work as a research fellow at the Nanyang Technological University in Singapore.
During her PhD work, Sun studied base station antenna elements and multi-band antenna arrays on cell phone towers. One major issue in telecommunications is that different networks often are co-located. While it would make sense to place 4G and 5G antennas on the same tower, that is often not possible because the antennas operating at different frequencies interfere with one another. “Our solution was to integrate frequency selective chokes into the antenna structures to make antennas at different frequencies invisible to each other,” she says. “Some of the antenna techniques we’ve developed have been patented and commercialized.”
Ground-penetrating radar, which she began working on in Nanyang, is similar; it essentially uses an antenna that is tuned to produce electromagnetic waves that travel into the ground or a structure. When the waves hit an object in the ground and bounce back, the recorded signal contains lots of potential data. However, accessing and interpreting that data is difficult. Sun is using new antenna designs and hardware as well as AI-powered software to declutter that data and pull out rich information, including size, shape, diameter and electrical properties of subsurface object.
“My ultimate goal in this research direction is to develop an intelligent system that can automatically and flexibly acquire and process the signals from the subsurface environment, extract key information, and achieve high resolution imaging of the subsurface system,” she says. “I think this kind of intelligent system could shape the way we perceive and interact with the hidden world around us.”
The technology could have a wide range of uses. For instance, in Singapore, a city full of very old, well-maintained trees, Sun and her colleagues tested her device by inspecting and mapping tree root systems. She says the technology could also be very useful in diagnosing the health conditions of buildings and structures in a nondestructive way.
At UW-Madison, she says she’s excited to continue her work and discover other potential applications in civil, geological and biomedical engineering and says there are also possible uses in space exploration. “Because my research is highly interdisciplinary, I’m very excited about joining this vibrant and collaborative research environment,” she says.