Autonomous and semi-autonomous systems need active illumination to navigate at night or underground. However, for defense applications, this requirement enables adversaries to detect a vehicle’s presence, in some cases from long distances away.
DARPA is trying to resolve this dilemma with its Invisible Headlights program. The research effort seeks to discover and quantify information contained in ambient thermal emissions in various environments and create new passive 3D sensors and algorithms to exploit that information.
“We’re aiming to make completely passive navigation in pitch dark conditions possible,” said Joe Altepeter, program manager in DARPA’s Defense Sciences Office, in a statement. “In the depths of a cave or in the dark of a moonless, starless night with dense fog, current autonomous systems can’t make sense of the environment without radiating some signal—whether it’s a laser pulse, radar or visible light beam—all of which we want to avoid. If it involves emitting a signal, it’s not invisible for the sake of this program.”
The researcher’s premise is since everything—whether animate and inanimate—gives off some thermal energy, the goal is to find out what information can be captured from even an extremely small amount of thermal radiation. In turn, this information would be used to develop algorithms and passive sensors into a 3D scene for navigation.
According to DARPA. the program includes three phases: 1) Discovery – to determine if thermal emissions contain sufficient information to enable autonomous driving at night or underground; 2) Optimization – to refine models, experimental designs, and ensure system feasibility for achieving 3D vision at both low speeds (<25 mph) and high speeds (>25 mph); and 3) Advanced Prototypes – to build and test passive demonstration systems that compete with active sensors.
“If we’re successful, the capability of Invisible Headlights could extend the environments and types of missions in which autonomous assets can operate—at night, underground, in the arctic, and in fog,” Altepeter said. “The fundamental understanding of what information is available in ambient thermal emissions could lead to advances in other areas, such as chemical sensing, multispectral vision systems, and other applications that exploit infrared light.”