Article
Optics
Zhenzhong Lu, Yuping Cao, Tao Peng, Biao Han, Qian Dong
Summary: LD-NLOS is an imaging technique based on the laser Doppler coherent detection method. It decodes the information of the detected object hidden in the intermediate scattering surface by analyzing the frequency and light intensity characteristics of the scattered signal. Without relying on complicated back-end algorithm processing and expensive experimental detection cost, this technique can detect the target's vibration velocity and stably reconstruct its 2D shape.
Article
Optics
JinHui He, ShuKong Wu, Ran Wei, YuNing Zhang
Summary: This study proposes a deep learning framework combined with a standard RGB camera to achieve object imaging and dynamic tracking. Through simulation experiments and physical scene tests, the method demonstrates superior positioning accuracy and imaging speed. The technique has diverse applications, including security surveillance, military reconnaissance, and autonomous driving.
Article
Multidisciplinary Sciences
Sheila Seidel, Hoover Rueda-Chacon, Iris Cusini, Federica Villa, Franco Zappa, Christopher Yu, Vivek K. Goyal
Summary: This research demonstrates a non-line-of-sight imaging method that can reconstruct dynamic scenes by utilizing occlusion and a sensor array to estimate the locations and sizes of moving foreground objects and generate a static background map.
NATURE COMMUNICATIONS
(2023)
Article
Optics
Takahiro Sasaki, Erich N. Grossman, James R. Leger
Summary: At THz frequencies, building materials with mirror-like reflectivity can be used to accurately estimate the 3D spatial location of non-line-of-sight objects. By employing a custom THz measurement setup and a refocusing algorithm, the accurate location of hidden objects can be determined.
Article
Optics
Zibin Liu, Haibo Liu, Zhaokun Zhu, Junyao Song
Summary: A method for accurate and robust pose estimation for uncooperative spacecraft using time-of-flight and gray-scale cameras is proposed. The approach establishes 2D-3D line correspondences for pose estimation, achieving significantly high accuracy when dealing with completely unknown models.
Article
Optics
Ahmed B. Ayoub, Joowon Lim, Elizabeth E. Antoine, Demetri Psaltis
Summary: A new approach to optical diffraction tomography (ODT) based on intensity measurements is presented using the Wolf transform, which shows unexpected behavior in 3D reconstruction. While this reconstruction does not provide quantitative refractive index information, it offers interesting qualitative information and possibilities for localizing nanoparticles in biological samples.
Article
Optics
Hakon J. D. Johnsen, Juan C. Minano, Jan Torgersen
Summary: Line-focus solar concentrators have been limited by the 2D concentration limit, but we propose a new design principle that bypasses this limit and achieves higher concentration ratios. By combining the concepts of etendue squeezing and tracking integration, we demonstrate a design example and provide efficiency values under different design conditions. This design principle opens up the design space for high-concentration line-focus solar concentrators and allows for a reconsideration of the trade-off between concentration and acceptance angle.
Article
Astronomy & Astrophysics
Aditya Vijaykumar, Avinash Tiwari, Shasvath J. Kapadia, K. G. Arun, Parameswaran Ajith
Summary: This study investigates the prospects of detecting the acceleration of compact binary coalescence (CBC) events in gravitational wave observations. The results show no evidence of line-of-sight acceleration in previously observed binary neutron star mergers. It is concluded that future observations using LIGO, XG detectors, and DECIGO could provide more precise measurements of accelerations for typical binary neutron stars.
ASTROPHYSICAL JOURNAL
(2023)
Article
Automation & Control Systems
Dongfang Li, Jiechao Zhou, Yanwei Huang, Dali Zhang, Ping Li, Aiguo Song
Summary: This study investigates the trajectory tracking strategy of a snake robot with sideslip disturbance and unknown model parameters. An adaptive anti-sideslip strategy using the Integral Line-of-Sight (ILOS) function is proposed to improve the trajectory tracking performance. The proposed controller considers the uncertainty and time variability of environmental parameters, and compensates for the joint input using adaptive update laws. Stability analysis and simulation experiments verify the effectiveness of the strategy.
IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING
(2023)
Article
Computer Science, Artificial Intelligence
Xiaofeng Yang
Summary: Target tracking provides important location-based services, and this paper proposes a novel online sequential learning algorithm IRELM to address the NLOS target tracking problem. IRELM can train RNN inputs one-by-one and adaptively update the weights. Extensive simulations and experiments demonstrate the superior tracking performance and feasible complexity of IRELM over existing Deep Learning methods.
COMPLEX & INTELLIGENT SYSTEMS
(2023)
Article
Computer Science, Artificial Intelligence
Ruixu Geng, Yang Hu, Zhi Lu, Cong Yu, Houqiang Li, Hengyu Zhang, Yan Chen
Summary: This paper proposes a novel passive NLOS imaging framework called NLOS-OT based on manifold embedding and optimal transport, aiming to reconstruct high-quality complicated hidden scenes. It also introduces the first large-scale passive NLOS imaging dataset, NLOS-Passive, for evaluating the performance of algorithms.
IEEE TRANSACTIONS ON IMAGE PROCESSING
(2022)
Article
Optics
Tianrong Xu, Yong Ruan, Yun Wu, Tao Tang
Summary: An optimized controller based on Youla-Kucera parameterization is proposed to improve vibration rejection and target tracking performance in optical tracking systems. Low-frequency performance was enhanced using an optimized Q(31)-filter, and stability and robustness of the control configuration were analyzed.
OPTICAL ENGINEERING
(2022)
Article
Engineering, Electrical & Electronic
Christopher A. Metzler, David B. Lindell, Gordon Wetzstein
Summary: Keyhole imaging technology captures transient measurements along a single optical path to recover the shape and position of objects. It provides a solution to the limitations of existing NLOS techniques, allowing for more efficient imaging without the need to scan large areas.
IEEE TRANSACTIONS ON COMPUTATIONAL IMAGING
(2021)
Article
Chemistry, Analytical
Seungwoo Jang, Ui-Hyeon Shin, Kwangsu Kim
Summary: Non-line-of-sight (NLOS) imaging aims to visualize hidden scenes using optical or acoustic equipment. In this study, we propose NLOS imaging using acoustic equipment inspired by echolocation and utilize deep-learning models to overcome the challenges of echoes interfering with each other.
Article
Multidisciplinary Sciences
Eitam Arnon, Assaf Uzan, Michal Handel, Shlomo Cain, Sivan Toledo, Orr Spiegel
Summary: Many environmental and ecological studies require line of sight (LOS) and/or viewshed analyses, but the existing tools are either too restrictive, inaccessible or pricey and difficult to use. Therefore, we developed ViewShedR, a free, open-source and intuitive graphical user-interface application for performing LOS calculations. ViewShedR allows effective tower deployment for tracking and other ecological applications.
ROYAL SOCIETY OPEN SCIENCE
(2023)
Article
Optics
Jonathan Klein, Martin Laurenzis, Matthias B. Hullin, Julian Iseringhausen
Article
Computer Science, Software Engineering
Bosheng Li, Jacek Kaluzny, Jonathan Klein, Dominik L. Michels, Wojtek Palubicki, Bedrich Benes, Soren Pirk
Summary: A novel method for reconstructing the 3D geometry of botanical trees from single photographs is introduced, addressing the challenges of faithfully reconstructing a tree from single-view sensor data. The method defines a reconstruction pipeline based on three neural networks, using radial bounding volumes to grow realistic branching for the tree crown and evaluating reconstructed geometries with several metrics.
ACM TRANSACTIONS ON GRAPHICS
(2021)
Article
Engineering, Electrical & Electronic
Martin Laurenzis, Trevor Seets, Emmanuel Bacher, Atul Ingle, Andreas Velten
Summary: Single-photon sensitive image sensors are widely used in passive imaging applications to capture accurate images under challenging lighting conditions and scene motion. By comparing different design choices in the processing pipeline, we have found an effective method to improve signal-to-noise ratio and resolution, achieving excellent reconstruction results for fast-moving objects.
JOURNAL OF ELECTRONIC IMAGING
(2022)
Article
Optics
Martin Laurenzis, Frank Christnacher
Summary: In this study, we present a method for stand-off characterization of sprayed water fog in the time domain. By measuring transient signatures of reflected photons and reconstructing the scattered photon paths, we successfully determine the fog's mean scattering length and reconstruct the scene using virtual wavefronts. This research is of great importance for characterization tools and enhanced imaging in scattering media.
Article
Environmental Sciences
Martin Laurenzis, Frank Christnacher
Summary: Cavity exploration is crucial for optical remote sensing and has various applications. We utilized single photon-counting avalanche diode cameras to capture changes in cavities and developed analytical models to estimate their sizes. Experimental evaluations showed that our models can provide initial estimates for cavities of different characteristics.
JOURNAL OF APPLIED REMOTE SENSING
(2023)
Proceedings Paper
Optics
F. Christnacher, M. Laurenzis
Summary: The recent development of single-photon avalanche diode (SPAD) based sensors has revolutionized advanced imaging and contributed to the growth of computational imaging. This paper demonstrates the visualization of transient propagation waves in cavities using ultra-short laser pulses and proposes a rapid evaluation method for cavity volume. This method is significant for disaster assessment, geological/archaeological excavations, and extraterrestrial missions.
EMERGING IMAGING AND SENSING TECHNOLOGIES FOR SECURITY AND DEFENCE VII
(2022)
Proceedings Paper
Optics
M. Laurenzis, F. Christnacher
Summary: This paper provides an overview of various active and passive SPAD imaging techniques coupled with laser illumination or ambient light, with a focus on military applications. By combining computational imaging, these emerging sensor technologies can access previously inaccessible information and extend the perceptual range of sensors.
EMERGING IMAGING AND SENSING TECHNOLOGIES FOR SECURITY AND DEFENCE VII
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
M. Laurenzis, T. Seets, E. Bacher, A. Ingle, A. Velten
Summary: This study demonstrates the use of single photon-counting avalanche photo-diode (SPAD) to measure the photon flux from uncorrelated single photons, and explores the relationship between the sensor photon count rate and the intensity or radiant flux reflected from surfaces. Various de-noising strategies and the impact of motion blur are examined, along with the application of a fast super-resolution neural network (FSRCNN) to scale images for super-resolution enhancement.
EMERGING IMAGING AND SENSING TECHNOLOGIES FOR SECURITY AND DEFENCE VI
(2021)
Proceedings Paper
Computer Science, Artificial Intelligence
Trevor Seets, Atul Ingle, Martin Laurenzis, Andreas Velten
Summary: SPADs are image sensing technology with extreme low-light sensitivity and picosecond timing resolution, used in photon-starved scenarios. Researchers propose an algorithm to estimate pixel motion from SPAD camera data and dynamically adapt integration windows to reduce motion blur. The feasibility of the method is demonstrated on real-world data captured using a 32 x 32 SPAD camera.
2021 IEEE WINTER CONFERENCE ON APPLICATIONS OF COMPUTER VISION (WACV 2021)
(2021)
Proceedings Paper
Quantum Science & Technology
Martin Laurenzis
EMERGING IMAGING AND SENSING TECHNOLOGIES FOR SECURITY AND DEFENCE V; AND ADVANCED MANUFACTURING TECHNOLOGIES FOR MICRO- AND NANOSYSTEMS IN SECURITY AND DEFENCE III
(2020)
Proceedings Paper
Optics
Martin Laurenzis, Martin Rebert, Stephane Schertzer, Emmanuel Bacher, Frank Christnacher
LASER RADAR TECHNOLOGY AND APPLICATIONS XXV
(2020)
Proceedings Paper
Optics
F. Christnacher, M. Laurenzis, Y. Lutz, A. Matwyschuk
ELECTRO-OPTICAL REMOTE SENSING XIII
(2019)
Proceedings Paper
Optics
Martin Laurenzis, Martin Rebert, Emmanuel Bacher, Stephane Schertzer
ELECTRO-OPTICAL REMOTE SENSING XIII
(2019)
Proceedings Paper
Optics
Martin Laurenzis, Martin Rebert, Stephane Schertzer, Frank Christnacher
LASER RADAR TECHNOLOGY AND APPLICATIONS XXIV
(2019)