The technique used in this new study is actually similar to what happens in a lidar system used in many autonomous vehicle systems (though Tesla famously eschews use of laser-based vision systems in its tech stack). CMU and its partner institutions use ultrafast laser light in their system, bouncing it off a wall to light an object hidden around a corner.
Sensors then capture the reflected light when it bounces back, and researchers measure and calculate how long it took for the reflected light to return to the point of origin. Taking a number of measurements, and using information regarding the target object’s geometry, the team was able to then reconstruct the objects with remarkable accuracy and detail. Their method was so effective that it even works through semi-osbscuring materials, including heavy paper — another big benefit when it comes to its potential for use in environment sensors that work in real-world conditions.