Thermal 3D Perception in Low Contrast Environments

A. Filippov, O. Filippova
Elphel, Inc., Utah, United States

Poster stand number: T146

Keywords: Thermal 3D, LWIR depth sensing, motion blur mitigation, contrast improvement, passive ranging

We invented a novel method to improve 3D thermal imaging contrast over an order of magnitude, revolutionizing thermal imaging and enabling long-range, day/night, passive 3D perception for ground and aerial systems with COTS thermal sensors. Our technology mitigates the uncooled thermal sensors' limitations: low sensitivity, low resolution, and high thermal inertia. The novel sensor configuration, calibration methods, and image processing algorithms improve the microbolometer-based 3D perception exceeding the performance of much larger, more expensive, and limited lifetime cryogenic cooled sensors. Additionally, our method of interscene accumulation of the intrascene correlations results in the system's Noise Equivalent Temperature Difference (NETD) of 2 mK and better. We increase the contrast of the thermal images and compensate for the uncooled image sensors' thermal inertia by using massive non-collinear arrays of thermal sensors. The conventional binocular stereo systems fail to fully utilize the captured data in the image pair as only the mismatch along the epipolar lines contributes to the depth calculation. Multiple non-collinear sensor configuration allows dynamic selection of the stereo-pairs perpendicular to the direction of motion blur, effectively reducing thermal inertia to below 1 ms.