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J. Eur. Opt. Society-Rapid Publ. 22, 40( 2026)
NLOS scene. This reduces performance variations that depend on the target position in comparison to single illumination schemes. Second, increased variation of illumination and detection pairs further confine the feasible target position as explicitly elaborated for the ellipsoid based backprojection reconstruction.
For single target localization scenarios, LoG based edge filtering of the reconstruction as commonly done in FBP NLOS imaging does not adequately counteract pulsewidth-induced temporal smearing that enlarges the feasible target region. Preprocessing the temporal measurement data by explicitly managing pulse widths outperforms filtering of the reconstruction result. Matched filtering was used to incorporate all signal photons received, posing an additional advantage over spatial edge detection that relies only on the first part of the pulse form. This fits in with the endeavor to develop a photon-efficient NLOS system, to address the limited emissions in eye-safe operation.
The presented system can be developed further into a hybrid LiDAR-NLOS system with an additional spatially broadened laser source that illuminates the detector’ s field of view, known as solid-state Flash-LiDAR. A direct ToF measurement can determine the orientation and the system’ s position relative to the relay wall, which is necessary to process the NLOS measurement. One application of this eye-safe compact hybrid system could be the localization of persons beyond the line of sight on an upper floor through a window, using the ceiling as the relay wall.
Funding This research received no external funding.
Conflicts of interest The authors have nothing to disclose.
Data availability statement
The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.
Author contribution statement
Conceptualization, K. A. and M. L.; Methodology, K. A. and J. K.; Software, K. A. and J. K.; Validation K. A., J. K. and M. L.; Investigation, K. A.; Writing – Original Draft Preparation, K. A. and J. K.; Writing – Review & Editing, J. K., M. L. and A. G; Visualization, K. A. and J. K.; Supervision, M. L. and A. G.
All authors have read and agreed to the submitted version of the manuscript.
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Converting non-confocal measurements into semi-confocal