Passive 3D location estimation of non-line-of-sight objects from a scattered thermal infrared light field

Takahiro Sasaki, Connor Hashemi, James R. Leger

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


We propose a novel passive procedure to estimate the 3D location of non-line-of-sight objects by measuring the light field of scattered long-wavelength infrared radiation. By scanning an infrared camera in a horizontal plane, the scattered light is collected as a light field cube. We introduce mathematics that separate the weak information-bearing signal in the light field cube from residual scattered light and utilize this information to determine highly precise object locations. Finally, we experimentally demonstrate the 3D localization procedure in a life-sized hallway consisting of diffusive walls using human-temperature non-line-of-sight objects.

Original languageEnglish (US)
Pages (from-to)43642-43661
Number of pages20
JournalOptics Express
Issue number26
StatePublished - Dec 20 2021

Bibliographical note

Funding Information:
Defense Advanced Research Projects Agency (DARPA), REVEAL Program, HR0011-16-C-0024. Sasaki designed and conducted the research on the NLOS localization procedure and the analysis on the localization accuracy, performed the experiments, and drafted the paper. Hashemi developed the automated IR light field measurement setup including a pixel-tracking system. Leger provided the fundamental consept of this study, proposed use of longer wavelength light for extending localization performance, and suggested the quasi-real-time measurement strategy. All of authors read and approved the final manuscript. We would like to thank Dr. Di Lin for technical discussions and Prof. Jarvis Haupt for meaningful advice on the signal enhancement process. Portions of this work were presented at the OSA Imaging and Applied Optics Congress (COSI) in 2021 [39].

Publisher Copyright:
© 2021 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement


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