Radar. Lidar. Cameras. They’re the components that help give autonomous vehicles from Uber, GM’s Cruise Automation, Google spinoff Waymo, and countless others a sense of their surroundings. But WaveSense CEO Tarik Bolat thinks they have a blind spot.

“A massive transformation in transportation and mobility is underway around the world as autonomous systems advance at an unprecedented pace,” Bolat said. “But before broad adoption of self-driving vehicles can occur, navigation safety and reliability must improve significantly, particularly in adverse weather conditions like snow, rain, and fog.”

Enter WaveSense’s ground-penetrating radars (GPR), which leverage a 12-element antenna array to send very high frequency (VHF) electromagnetic pulses up to 10 feet below the ground. Those waves reflect off of underground features like pipes, roots, rocks, and dirt, which helps build a basemap that an onboard computer correlates into a three-dimensional, GPS-tagged subterranean database.

The radars can penetrate rain, fog, dust, and snow, Bolat said, making them ideally suited to inclement weather. And with the help of an algorithm and WaveSense’s underground maps, they’re able to iteratively narrow in on the car’s location as it moves.

They have other uses, too. GPR might one day be used to alert municipalities when roads are in need of maintenance or for underground navigation.

The technology has its origins at the Massachusetts Institute of Technology’s Lincoln Laboratory for the United States Department of Defense, where it was developed for military vehicles deployed in regions with poor or nonexistent road markings. (The first systems underwent testing in Afghanistan in 2013.)

Lincoln Laboratory researchers took a step toward commercialization in 2016, when they demonstrated that a sports utility vehicle equipped with the system could stay within centimeters of its lane on a road freshly coated with snow.

“We’ve achieved 4cm lateral side-to-side accuracy at highway speeds and 6cm lateral accuracy in snowstorms in the middle of the night,” Bolat said. “I don’t believe any of the autonomous vehicle companies can lay claim to this.”

To be clear, WaveSense isn’t advocating the replacement of lidar, radar, or cameras with GPR — Bolat acknowledges that they perform mapping and object detection tasks quite well in most scenarios. Instead, it’s positioning its solution as a complement to existing sensors and as a fallback for when those sensors fail — in heavy rain and fog, for instance, or in sand and dust storms.

“The ground-penetrating radar technology that successfully protected our troops in Afghanistan from dangerous situations will accelerate the commercialization of self-driving vehicles, and will significantly reduce civilian autonomous vehicle fatalities,” said Byron Stanley, WaveSense cofounder and chief technology officer and a lead researcher on Lincoln Laboratory’s GPR program, in a statement. “That mission has driven our work and our passion for a decade and is what propels us forward now.”

Despite GPR’s merits, it won’t necessarily be an easy sell. Getting the sort of localized tracking Bolat describes set up in major cities would be a massive undertaking — each road would need to be scanned individually. And competing solutions exist in the form of monitoring systems like NIRA Dynamics’ Road Surface Information (RSI), which uses machine learning algorithms to aggregate data from vehicle sensors, controllers, and camera feeds as map layers.

But Bolat remains confident about GPR’s efficacy. He’s not the only one — WaveSense has several pilots underway with automotive partners.

“[Our] technology radically improves the safety of self-driving vehicles in all conditions and provides the confidence and reliability our sector must demonstrate in order to earn the public’s trust,” he said.

WaveSense is currently raising a $ 3 million seed round led by Rhapsody Ventures Partners.