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Photogrammetry systems are widely used in industrial manufacturing applications as an assistance measurement tool. Not only does it provide high-precision feedback for assembly process inspection and product quality assessment, but also it can improve the flexibility and robustness of manufacturing systems and production lines. However, with growing global competition and demands, companies are forced to enhance production efficiency, shorten production lifecycle and increase product variety by incorporating reconfigurable factory design that can meet challenging timeline and requirements. Although dynamic facility layout is widely investigated, the position selection for the photogrammetry system in dynamic manufacturing environment is usually overlooked. In this paper, dynamic layout of the V-STARS photogrammetry system is investigated and optimised in a digital-twin environment using deep reinforcement learning. The learning objectives are derived from the field of view (FoV) evaluation from point clouds 3D reconstruction, and collision detection from the digital twin simulated in Visual Components. The application feasibility of the proposed dynamic layout optimisation of the V-STARS photogrammetry system is verified with a real world industrial application. [ABSTRACT FROM AUTHOR]

One of the primary challenges in ring single‐element photoacoustic tomography systems is the low image quality in areas away from the center of the ring. This is mainly due to the limited field of view (FOV) of each transducer, which in turn reduces the imaging FOV. To address this shortcoming, we have put forward a practical and straightforward solution to enhance the FOV of circular scanning‐based photoacoustic tomography (CS‐PAT). This is accomplished by placing transducers at different angles instead of using a single transducer placed at a normal angle to the imaging target. We also modified the ring scanner inner wall surface to significantly reduce photoacoustic reverberation. By imaging several phantoms, we show a significant improvement in the images generated by our system imaging from 4.1 to over 7 for the signal‐to‐noise ratio and structural similarity index increased from 41% to 70%. [ABSTRACT FROM AUTHOR]

Due to the increasing weight of electric vehicles, advanced tyre technology is urgently needed. In particular, there is a need for dynamic contact analysis to determine the energy interaction between tyres and road surfaces. However, the methods developed to date are limited in that they require either numerous contact patches inside the tyre or sensor devices on the ground. In this study, we propose a new method for dynamic tyre-ground contact analysis that overcomes these limitations. By installing a two-dimensional image sensor inside the tyre, deformations can be observed and quantified three-dimensionally during vehicle operation. This method advances tyre engineering through innovative analysis of tyre deformation during operation. [ABSTRACT FROM AUTHOR]

The purpose of this review is to analyze the trend in optical features and flexibility changes of flexible ureteroscopes over the past decades, and determine the correlation of individual parameters with release period as well as with dimensional parameters. Flexible ureteroscopes mentioned in the literature or those commercially available were searched. To minimize the search bias, the instruments were grouped by release date time-periods of < 2000 year, 2000–2009, 2010–2019, and 2020 onwards. The final review included only those instrument models for which data on minimum and maximum depth of field, field of view, direction of view, and deflection degree had been determined. The correlation among features investigated as well as with release period was also determined. 61 models of flexible ureteroscopes (27 fibreoptic and 34 digital scopes) were included. Among the different features investigated among fiberoptic endoscopes, minimum depth of field positively and negatively correlated with channel size and field of view, respectively, whereas maximum depth of view and field of view positively correlated with overall shaft and deflection degree, respectively. Up and down deflection strongly correlated with each other and both were negatively proportional to the distal tip size. For the digital endoscopes, minimum depth of field negatively and positively correlated with distal tip size and working length, respectively. Maximum depth of field positively correlated with field of view, whereas the latter was negatively proportional to the overall shaft. As for the fiberoptic counterparts, up and down deflection strongly correlated with each other. Field of view, up and down deflection of fiberoptic flexible ureteroscopes, were significantly increased among fiberoptic and digital endoscopes over decades. As flexible ureteroscopy technology has evolved, there has been a trend towards increasing field of view with up and down deflection. Given the importance of scope ergonomics, one aspect of this popularity is the improvement of optical characteristics and deflection degree, which significantly correlates with the release period. [ABSTRACT FROM AUTHOR]

Lensless fluorescence microscopy (LLFM) has emerged as a promising approach for biological imaging, offering a simplified, high-throughput, portable, and cost-effective substitute for conventional microscopy techniques by removing lenses in favor of directly recording fluorescent light on a digital sensor. However, there are several obstacles that this novel approach must overcome, such as restrictions on the resolution, field-of-view (FOV), signal-to-noise ratio (SNR), and multicolor-imaging capabilities. This review looks at the most current developments aimed at addressing these challenges and enhancing the performance of LLFM systems. To address these issues, computational techniques, such as deconvolution and compressive sensing, hardware modifications and structured illumination, customized filters, and the utilization of fiber-optic plates, have been implemented. Finally, this review emphasizes the numerous applications of LLFM in tissue analysis, pathogen detection, and cellular imaging, highlighting its adaptability and potential influence in a range of biomedical research and clinical diagnostic areas. [ABSTRACT FROM AUTHOR]

Measuring the eyebox of a near‐eye display is a complex and time‐consuming process. The recent introduction of the Draper eyebox method offers an opportunity to simplify the process and dramatically reduce the measurement time. This study compares the Draper method with the standard goniometric method with both pupil and eye rotation, and discusses its correlation. [ABSTRACT FROM AUTHOR]

The systems with horn elements are widely used as receiving components in applications of solar concentrators, for sensing in biomedicine, THz technology, etc. In many cases, using the horns as focusing elements in radiation detection arrangements is preferable to lenses. The article develops a theory for gain and field of view of a conical horn under normal and oblique illumination applicable in a wide spectrum ranging from ultraviolet to Sub-mm-Wave/Terahertz. The model assumes the introduction of fictional conical horns (identical to the real one) located in fictional concentric spheres. The proposed model makes it possible to determine the gain level for any geometric form of the horn and any number of beam reflections on its internal surface when a reflection coefficient is 1. The results of gain dependence on the incidence angle of illumination are analyzed depending on the configuration of the conical horn. It is shown that with an increase in the horn length relative to the optimal value, the distribution of gain on the angle of illumination tends to be Π-shaped, and the angle of view tends to apex angle. [ABSTRACT FROM AUTHOR]

In this paper, a novel method is demonstrated to sustain vehicle-to-vehicle (V2V) communication on curvy roads via the arrangement of the lateral position of a self-angle-adjustable mirror–reflective road sign (SAAMRS) and light-direction-sensing wide-angle complementary photodiodes (CPDs). Visible light communication (VLC) between vehicles attracts attention as a complementary technology to radio-frequency-based (RF-based) communication technologies due to its wide, license-free spectrum and immunity to interferences. However, V2V VLC may be interrupted on curvy roads due to the limited field of view (FOV) of the receiver or the line of sight (LOS) being interrupted. To solve this problem, an experiment was developed using an SAAMRS along with wide-angle light-direction-sensing CPDs that used a precise peak detection (PPD) method to sustain communication between vehicles in dynamic environments by rerouting the incident light with the highest signal intensity level to the receiver vehicle on curvy roads. We also used real images of curvy roads simulated as polynomials to calculate the necessary rotation angles for the SAAMRS and regions where communication exist. Our experimental results overlapped almost completely with our simulations, with small errors of approximately 4.8% and 4.4% for the SAAMRS angle and communication region, respectively. [ABSTRACT FROM AUTHOR]

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Significance: Light-sheet fluorescence microscopy (LSFM) has emerged as a powerful and versatile imaging technique renowned for its remarkable features, including high-speed 3D tomography, minimal photobleaching, and low phototoxicity. The interference light-sheet fluorescence microscope, with its larger field of view (FOV) and more uniform axial resolution, possesses significant potential for a wide range of applications in biology and medicine. Aim: The aim of this study is to investigate the interference behavior among multiple light sheets (LSs) in LSFM and optimize the FOV and resolution of the light-sheet fluorescence microscope. Approach: We conducted a detailed investigation of the interference effects among LSs through theoretical derivation and numerical simulations, aiming to find optimal parameters. Subsequently, we constructed a customized system of multi-LSFM that incorporates both interference light sheets (ILS) and noninterference light-sheet configurations. We performed beam imaging and microsphere imaging tests to evaluate the FOV and axial resolution of these systems. Results: Using our custom-designed light-sheet fluorescence microscope, we captured the intensity distribution profiles of both interference and noninterference light sheets (NILS). Additionally, we conducted imaging tests on microspheres to assess their imaging outcomes. The ILS not only exhibits a larger FOV compared to the NILS but also demonstrates a more uniform axial resolution. Conclusions: By effectively modulating the interference among multiple LSs, it is possible to optimize the intensity distribution of the LSs, expand the FOV, and achieve a more uniform axial resolution. [ABSTRACT FROM AUTHOR]

Metalens, a metasurface with a focusing phase, has been the focus of research due to its immense potential for use in imaging and display technology. Traditional lens and optical imaging systems rely on phase accumulation, however metalens with subwavelength structures provide a disruptive path for miniaturized optical imaging systems by allowing unfettered modulation of incident light's phase and amplitude. Recently, extensive efforts have been devoted to exploring new design strategies, new functionalities, and possible applications. This paper reviews the development, principle, classification, and research status of metalens. In particular, this review focuses on the progress and challenges of improving imaging quality and expanding imaging diversity, including improvements of resolution, enhancement of depth of field, extension of field of view, and achromatism. Lastly, the prospects of metalens in the future display are summarized, and the application potentials of metalens in novel 3D display, intelligent and bionic display, as well as nano‐pixelate light‐emitting display (NLED) are emphasized. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the prevalence of incidental findings and need for further dental treatment and analyse the influence of size of field-of-view (FOV) and age in cone beam computed tomography (CBCT) for pre-implant planning. Methods: 404 CBCT scans were examined retrospectively for incidental findings and need for further dental treatment. Incidental finding-frequencies and need for further treatment were assessed for different age (< 40 years, 40–60 years, > 60 years) and FOV groups (small, medium, large). Intraexaminer and interexaminer agreements were evaluated. Results: In 82% of the scans at least one incidental finding was found, with a total of 766 overall. More incidental findings were found in scans with large FOV (98% vs. 72%, OR = 22.39 large vs. small FOV, p < 0.0001) and in scans of patients > 60 years (OR = 5.37 patient's age > 60 years vs. < 40 years, p = 0.0003). Further dental treatment due to incidental findings was needed in 31%. Scans with large FOV were more likely to entail further treatment (OR = 3.55 large vs. small FOV, p < 0.0001). Partial edentulism and large FOV were identified as risk factors for further treatment (p = 0.0003 and p < 0.0001). Further referral of the patient based on incidental findings was judged as indicated in 5%. Intra- and inter-examiner agreements were excellent (kappa = 0.944/0.805). Conclusions: A considerable number of incidental findings with need for further dental treatment was found in partially edentulous patients and in patients > 60 years. In pre-implant planning of elderly patients, the selection of large FOV CBCT scans, including dentoalveolar regions not X-rayed recently, help to detect therapeutically relevant incidental findings. [ABSTRACT FROM AUTHOR]

The human visual system evolved in environments with statistical regularities. Binocular vision is adapted to these such that depth perception and eye movements are more precise, faster, and performed comfortably in environments consistent with the regularities. We measured the statistics of eye movements and binocular disparities in virtual-reality (VR) - gaming environments and found that they are quite different from those in the natural environment. Fixation distance and direction are more restricted in VR, and fixation distance is farther. The pattern of disparity across the visual field is less regular in VR and does not conform to a prominent property of naturally occurring disparities. From this we predict that double vision is more likely in VR than in the natural environment. We also determined the optimal screen distance to minimize discomfort due to the vergence-accommodation conflict, and the optimal nasal-temporal positioning of head-mounted display (HMD) screens to maximize binocular field of view. Finally, in a user study we investigated how VR content affects comfort and performance. Content that is more consistent with the statistics of the natural world yields less discomfort than content that is not. Furthermore, consistent content yields slightly better performance than inconsistent content.

Cone-beam computed tomography (CBCT) is a widely used imaging technique in interventional radiology. Although CBCT offers great advantages in terms of improving comprehension of complex angioarchitectures and guiding therapeutic decisions, its additional degree of radiation exposure has also aroused considerable concern. In this study, we aimed to assess radiation exposure and its influential factors in patients undergoing CBCT scans of the head and abdomen during interventional procedures. A total of 752 patients were included in this retrospective study. Dose area product (DAP) and reference air kerma (RAK) were used as measures of patient dose. The results showed that the median values of DAP were 53.8 (50.5–64.4) Gy⋅cm2 for head CBCT and 47.4 (39.6–54.3) Gy⋅cm2 for that of the abdomen. Male gender and body mass index (BMI) were characterized by increased DAP and RAK values in both head and abdominal CBCT scans. Larger FOV size was associated with a higher DAP but a lower RAK value, especially in head CBCT scans. Exposure parameters under automatic exposure control (AEC) also varied according to patient BMI and gender. In conclusion, the patients received slightly higher radiation doses from head CBCT scans than from those applied to the abdomen. BMI, gender, and FOV size were the key factors that influenced the radiation dose administered to the patients during CBCT scans. Our results may help to define and minimize patients’ exposure to radiation.

In the context of an ever-growing and complex orbital environment, space monitoring and spacecraft tracking is a must when it comes to mitigating space related challenges. In Space Surveillance and Tracking (SST) most radio detection techniques use high-gain directional antennas. Nevertheless, these antennas have a limited field of view (FoV), resulting in low detection probability and tracking duration for Low Earth Orbit (LEO) targets. This research presents an SST experimental hardware solution which is aimed at extending the field of view of a 1.8 m Ku-band parabolic dish by equipping it with a multifeed receiver. The incoming satellite signal undergoes processing and analysis utilizing a National Instruments featured software-defined radio (SDR) platform along with its corresponding software application. The field of view of the proposed solution is determined through simulation and experimental tests using a satellite beacon as a target signal. The research shows promising results regarding the use of multifeed structures in SST.

This paper introduces a method for computing reactive terminations for scatterer elements in antenna arrays. With the fixed scatterer elements, we shape embedded element patterns of sparse arrays to focus the radiation into a grating-lobe-free limited field of view. The reactive terminations of the scatterer elements are determined by optimizing reflection coefficients on a Riemannian manifold. In addition, we show that widening the grating-lobe-free field of view is possible by tilting the field of view. We design both 5-element linear and 4-by-4-element planar reactively loaded antenna arrays with 1.4-wavelength inter-element distances. The terminations of the scatterer elements are optimized so that the arrays cover either the broadside-located or the tilted grating-lobe-free field of view. The results obtained from the linear array are validated through measurements of manufactured prototypes.

Background: Insects have evolved complex visual systems and display an astonishing range of adaptations for diverse ecological niches. Species of Drosophila melanogaster subgroup exhibit extensive intra- and interspecific differences in compound eye size. These differences provide an excellent opportunity to better understand variation in insect eye structure and the impact on vision. Here we further explored the difference in eye size between D. mauritiana and its sibling species D. simulans. Results: We confirmed that D. mauritiana have rapidly evolved larger eyes as a result of more and wider ommatidia than D. simulans since they recently diverged approximately 240,000 years ago. The functional impact of eye size, and specifically ommatidia size, is often only estimated based on the rigid surface morphology of the compound eye. Therefore, we used 3D synchrotron radiation tomography to measure optical parameters in 3D, predict optical capacity, and compare the modelled vision to in vivo optomotor responses. Our optical models predicted higher contrast sensitivity for D. mauritiana, which we verified by presenting sinusoidal gratings to tethered flies in a flight arena. Similarly, we confirmed the higher spatial acuity predicted for Drosophila simulans with smaller ommatidia and found evidence for higher temporal resolution. Conclusions: Our study demonstrates that even subtle differences in ommatidia size between closely related Drosophila species can impact the vision of these insects. Therefore, further comparative studies of intra- and interspecific variation in eye morphology and the consequences for vision among other Drosophila species, other dipterans and other insects are needed to better understand compound eye structure–function and how the diversification of eye size, shape, and function has helped insects to adapt to the vast range of ecological niches. [ABSTRACT FROM AUTHOR]

Optical coherence tomography (OCT) is an extensively used imaging tool for disease monitoring in both age-related macular degeneration (AMD) and retinal vein occlusion (RVO). However, there is limited literature on minimum requirements of OCT settings for reliable biomarker detection. This study systematically investigates both the influence of scan size and interscan distance (ISD) on disease activity detection. We analyzed 80 OCT volumes of AMD patients and 12 OCT volumes of RVO patients for the presence of subretinal fluid (SRF), intraretinal fluid (IRF), and pigment epithelium detachment (PED). All volume scans had a scan size of 6 × 6 mm and an ISD of 125 µm. We analyzed both general fluid distribution and how biomarker detection sensitivity decreases when reducing scan size or density. We found that in AMD patients, all fluids were nearly normally distributed, with most occurrences in the foveal center and concentric decrease towards the periphery. When reducing the scan size to 3 × 3 and 2 × 2 mm, disease activity detection was still high (0.98 and 0.96). Increasing ISD only slightly can already compromise biomarker detection sensitivity (0.9 for 250 µm ISD against 125 µm ISD). [ABSTRACT FROM AUTHOR]

Cone-beam computed tomography (CBCT) is a widely used imaging technique in interventional radiology. Although CBCT offers great advantages in terms of improving comprehension of complex angioarchitectures and guiding therapeutic decisions, its additional degree of radiation exposure has also aroused considerable concern. In this study, we aimed to assess radiation exposure and its influential factors in patients undergoing CBCT scans of the head and abdomen during interventional procedures. A total of 752 patients were included in this retrospective study. Dose area product (DAP) and reference air kerma (RAK) were used as measures of patient dose. The results showed that the median values of DAP were 53.8 (50.5–64.4) Gy⋅cm2 for head CBCT and 47.4 (39.6–54.3) Gy⋅cm2 for that of the abdomen. Male gender and body mass index (BMI) were characterized by increased DAP and RAK values in both head and abdominal CBCT scans. Larger FOV size was associated with a higher DAP but a lower RAK value, especially in head CBCT scans. Exposure parameters under automatic exposure control (AEC) also varied according to patient BMI and gender. In conclusion, the patients received slightly higher radiation doses from head CBCT scans than from those applied to the abdomen. BMI, gender, and FOV size were the key factors that influenced the radiation dose administered to the patients during CBCT scans. Our results may help to define and minimize patients' exposure to radiation. [ABSTRACT FROM AUTHOR]

Omnidirectional photosensing is crucial in optoelectronic devices, enabling a wide field of view (wFoV) and leveraging potential applications for the Internet of Things in sensors, light fidelity, and photocommunication. The wFoV helps overcome the limitations of line‐of‐sight communication, and transparent photodetection becomes highly desirable as it enables the capture of optical information from various angles. Therefore, developing a photoelectric device with a 360° wFoV, ultra sensitivity to photons, power generation, and transparency is of utmost importance. This study utilizes a heterojunction of van der Waals SnS with Ga2O3 to fabricate a transparent photovoltaic (TPV) device showing a 360° wFoV with bifacial onsite power production. SnS/Ga2O3 heterojunction preparation consists of magnetron sputtering and is free from nanopatterning/nanostructuring to achieve the desired wFoV window device. The device exhibits a high average visible transmittance of 56%, generates identical power from bifacial illumination, and broadband fast photoresponse. Careful analysis of the device shows an ultra‐sensitive photoinduced defect‐modulated heterojunction and photocapacitance, revealed by the impedance spectroscopy, suggesting photon‐flux driven charge diffusion. Leveraging the wFoV operation, the TPV embedded visual and speech photocommunication prototype demonstrated, aiming to help visually and auditory impaired individuals, promising an environmental‐friendly sustainable future. [ABSTRACT FROM AUTHOR]

AbstractGaze interaction in virtual reality (VR) offers promising advantages in speed and hands-free operation. However, selecting a suitable selection mechanism in VR interfaces with different visual encodings remains a challenge. This research compares two visual input techniques and explores specific visual elements, including field of view (FOV), design style, and number of targets, with the goal of alleviating these problems. The pilot study identifies two search stages, and it also demonstrates a significant effect of FOV on search time. In the formal experiment, a gaze-based trigger experiment is employed to examine the selection performance of fixation and smooth pursuit. The results reveal that optimizing FOV and number of targets improves the triggering efficiency. Furthermore, fixation outperforms pursuit in terms of triggering time and accuracy under the same conditions, while cognitive load during triggering process remains relatively similar. These findings are expected to propose design recommendations to enhance fixation and pursuit within VR interfaces. [ABSTRACT FROM AUTHOR]

The FY-3E satellite plasma analyzer marks China's first detection of the characteristics, occurrence, and development of the typical plasma environment in the dawn–dusk orbit space. It provides data source support for operational space weather alerts and forecasts, helps ensure the in-orbit safety of the satellite, and accumulates space environment detection data for space environment modeling and space physics research. This paper gives a detailed introduction to the detection technology adopted by the FY-3E satellite plasma analyzer. We calibrated its performance through a calibration experiment and then analyzed and compared it with similar instruments in China. It is indicated that the instrument is capable of measuring an ion energy spectrum of 24 eV~32 keV and an electron energy spectrum of 23.7 eV~31.6 keV, its field of view reaches 180° × 90°, and the inversed measurement range of spacecraft absolute potential is better than −30 kV~+30 kV. All these contribute to a notably improved technology for plasma and satellite potential detection of China's LEO satellites. [ABSTRACT FROM AUTHOR]

We present the field of view (FOV) that can be achieved by near‐eye displays based on polarization volume grating(PVG). The effects of the refractive index and period parameter of PVG‐couplers on the FOV are investigated. In addition, we propose two wide‐FOV near‐eye displays featuring a PVG based dual‐channel waveguide. Both structures use the polarization properties of the PVG to propagate the field of view in separate channels. [ABSTRACT FROM AUTHOR]

Cone beam computed tomography (CBCT) has been widely used in various fields of dentistry. The diagnosis of root fractures, especially vertical root fractures (VRFs) with CBCT images, has been a research hotspot since then. Research on this area mainly includes the following five aspects: ① the diagnostic efficiency of CBCT images for root fractures; ② the influence of scanning parameters on the diagnostic accuracy of CBCT images in root fractures, such as scanning field of view, spatial resolution, tube current and tube voltage; ③ whether the application of image postprocessing techniques, especially metal artifact reduction (MAR), can improve the diagnostic accuracy of root fractures after root canal treatment and/or there is a post core in the root canal; ④ establishment and validation of clinical diagnosis model for vertical root fracture; and ⑤ application of artificial intelligence technology and contrast agent in root canals for the diagnosis of CBCT image in root fractures. Compared with periapical radiographs, CBCT images can improve the diagnostic accuracy of root fractures in nonendodontic treated teeth; however, for teeth that have undergone endodontic treatment, the diagnosis of VRF must be combined with clinical signs. Vertical bone resorption in the buccolingual (palatal) direction is a characteristic indicator of VRF. The width of the VRF is an important factor affecting the diagnostic accuracy, but the voxel size used in CBCT scanning is not a necessary factor affecting its diagnostic accuracy; the fracture direction does not affect the diagnostic accuracy of the VRF. Image postprocessing techniques, especially MAR, cannot improve the diagnostic accuracy of VRF and may also reduce the diagnostic efficiency, so they are not recommended for clinical application.

Over the years, deep reinforcement learning (DRL) has shown great potential in mapless autonomous robot navigation and path planning. These DRL methods rely on robots equipped with different light detection and range (LiDAR) sensors with a wide field of view (FOV) configuration to perceive their environment. These types of LiDAR sensors are expensive and are not suitable for small-scale applications. In this paper, we address the performance effect of the LiDAR sensor configuration in DRL models. Our focus is on avoiding static obstacles ahead. We propose a novel approach that determines an initial FOV by calculating an angle of view using the sensor's width and the minimum safe distance required between the robot and the obstacle. The beams returned within the FOV, the robot's velocities, the robot's orientation to the goal point, and the distance to the goal point are used as the input state to generate new velocity values as the output action of the DRL. The cost function of collision avoidance and path planning is defined as the reward of the DRL model. To verify the performance of the proposed method, we adjusted the proposed FOV by ±10° giving a narrower and wider FOV. These new FOVs are trained to obtain collision avoidance and path planning DRL models to validate the proposed method. Our experimental setup shows that the LiDAR configuration with the computed angle of view as its FOV performs best with a success rate of 98% and a lower time complexity of 0.25 m/s. Additionally, using a Husky Robot, we demonstrate the model's good performance and applicability in the real world. [ABSTRACT FROM AUTHOR]

The use of electro-optical imaging system for commercial, military, or surveillance missions, as well as space scientific missions, dates back to the first successful operation aboard the US Explorer-6 spacecraft, which was the first spacecraft to capture low-resolution images of the Earth's surface, and the Luna-3 space probe, which was the first spacecraft to send images of the lunar far side, in 1959. The technology underlying EO system have evolved over time, with advances in optics, electronics, and materials science leading to the development of more sophisticated and capable imaging sensors. Furthermore, the technological advances in sensors, optics, mechanics, material, signal and image processing algorithms have allowed EO payloads to become smaller, lighter, and more efficient while still providing high-quality imagery. Over 840 small spacecraft weighing less than 500 kg were launched, with 80% in the constellation segment and 20% as monolithic satellites (i.e., single spacecraft equipped with an electro-optical imaging instrument launched into space for various missions). In this paper, the electro-optical imaging systems of these spacecraft were reviewed using data from a variety of sources, including peer-reviewed journal publications, conference proceedings, mission webpages, and other publicly available satellite databases. Furthermore, the technological and commercial expansion of small spacecraft (< 500 kg) equipped with electro-optical imaging systems, as well as EO-COTS parametric performance values such as GSD, spectral range, field of view, and sensor type, are discussed through 2023, divided by spacecraft type: SSO satellites, Small spacecraft constellation, Deep space spacecraft, and EO commercialization. • The evolution of electro-optical imaging system. • Small spacecraft missions equipped with EO sensors. • Constellation of small satellite missions can provide comparable capability. • The advantages of an EO-based deep space spacecraft mission. • The main factors driving the market trend toward small spacecraft optical payload. [ABSTRACT FROM AUTHOR]

The study aimed to introduce a novel imaging method that generates large-coverage, weight-bearing, and 3D images of the whole spine. The proposed system comprises an X-ray tube, a flat panel detector, and a standing platform. The standing platform rotates the imaged subject, allowing for the acquisition of serial fluoroscopic images from different angles which can be used to create 3D images. To increase the longitudinal coverage, we apply a segmental scanning pattern in which the imaged region is scanned in segments and stitched. To address the issue of data inaccuracy between the segments, redundant areas are set at margins of the segmental images, and registration and stitching algorithms are applied. We conducted validation experiments to evaluate radiation dose and image quality. The dose was evaluated using the volume CT dose index (CTDIvol). For image quality evaluation, we measured the low-contrast and spatial resolution. Additionally, we conducted a clinical study consisting of 30 volunteers with adolescent idiopathic scoliosis who were imaged by our method, and the images were subjectively assessed based on image noise, artifacts, anatomical coverage, diagnostic confidence, and overall quality. The CTDIvol was 1.23 mGy, and the low-contrast resolution was 0.6% at 4 mm and the spatial resolution was 8 lp/cm. The clinical images were generally of good quality, with high scores for all factors evaluated. Our method successfully generates large-coverage, weight-bearing, and 3D images of the whole spine with high image quality and low radiation dose. It shows potential for wider clinical applications for various musculoskeletal conditions. [ABSTRACT FROM AUTHOR]

The field of view and single-star measurement accuracy are crucial metrics for assessing the performance of a star sensor. The field of view determines the spatial range of stars that can be captured by the sensor, while the single-star measurement accuracy determines the precision of attitude determination and control for the star sensor. The optical system of conventional star sensors is constrained by imaging relationships. Once the detector is determined, improving either the field of view or the single-star measurement accuracy will result in the degradation of the other. To address this issue, we propose an optical system for star sensors with accuracy performance varying with the field of view. By controlling the relationship between the field focal length of the optical system and the field of view, it is possible to simultaneously enhance both the field of view and the single-star measurement accuracy. We have designed corresponding optical systems to address the requirements for improving the single-star measurement accuracy and field of view. The design results confirm the feasibility of this star sensor. The star sensors are capable of simultaneously meeting the requirements for star pattern recognition and attitude determination, presenting broad application prospects in fields such as space navigation. [ABSTRACT FROM AUTHOR]

Background: The limited 70° field of view (FoV) used in standard laparoscopy necessitates maneuvering the laparoscope to view the ports, follow the surgical tools, and search for a target region. Complications related to events that take place outside the FoV are underreported. Recently, a novel laparoscopic system (SurroundScope, 270Surgical) was reported to dramatically expand the FoV from 70 to 270°. This study focuses on differences in performing laparoscopic cholecystectomy using the SurroundScope compared to the standard laparoscope. Methods: Forty-four laparoscopic surgeries were performed and video recorded. A subanalysis of 21 Cholecystectomies was performed and compared to 21 Cholecystectomies, performed with the standard laparoscope during the study period by the same surgeon. Results: No accidental or intraoperative adverse events occurred when using the SurroundScope. Subanalysis of 21 Cholecystectomies revealed shorter fog/smoke cleaning times using the SurroundScope compared to the standard scope (1.45 ± 5.08 sec vs. 54.95 ± 137.77 sec, p = 0.0454). Furthermore, operations performed with the SurroundScope had a shorter trocar placement duration (85.0 ± 40.9 sec vs. 111.3 ± 70.5 sec; p = 0.077), shorter time to achieve critical view of safety (9.5 ± 4.14 min vs. 15.8 ± 11.87 min; p = 0.015), and shorter procedure duration (31.9 ± 10.4 min vs. 42.9 ± 22 min; p = 0.025). In post-operative evaluations, the surgeon noted that tools could be continuously followed and ports were visible without camera manipulation. Also, the surgeon agreed that the procedure could be better planned due to the wide FoV and that surgical workflow was improved. Furthermore, the surgeon agreed that the procedure was safer using the SurroundScope. Conclusions: Initial results demonstrate the advantages of the SurroundScope over standard laparoscopy. By expanding the FoV, visualization is improved, the procedure is more efficient, significantly shorter and most important, patient safety, per surgeons' testimonials is improved. Further investigation to quantify these benefits in a larger group of patients and among various surgical procedures should be considered. [ABSTRACT FROM AUTHOR]

In Undersea visible light communication (UVLC) system, we investigate the effect of ambient noise, caused by solar noise under oceanic water. We investigate how undersea visible light communication systems perform when exposed to ambient noise brought on by sun radiation. We present a universal and analytical model that examines the impact of solar noise on communication link efficiency, specifically in regards to the bit error rate, also taking into account the beam spreading function. The performance of this UVLC link for different oceanic depth for different photodetectors in addition with variable transmitter field of view has been studied using simulation in the presence of subsea solar noise. Our results show that the maximum link distance for UVLC systems is only a few tens of meters in pure oceanic water. The findings are extremely helpful for designing UVLC linkages, which are most likely to be formed for variable depths. Since they clarify how ambient light affects the readings, in the actual deployment of UVLC systems. We studied the vertical undersea visible light communication link performance for some specific weak turbulence channel parameters with beam spreading function and observed that as the transmitter field of view increases from 0.25 to 0.75 mrad, the link distance decreases from 75 to 30 m and as the depth increases, impact of solar noise decreases and hence link distance coverage increases. Communication link distance for oceanic surface is 25 m for PIN photodiode and 48 m for Avalanche photodiode and as the depth increases i.e., 10 m, link distance for PIN photodiode is 28 m and 50 m for Avalanche photodiode, for the depth of 50 m, PIN photodiode based UVLC system covers the link distance of 30 m and Avalanche based UVLC system covers 52 m, and for 90 m depth PIN photodiode covers communication link distance of 32 m and Avalanche photodiode covers 55 m. [ABSTRACT FROM AUTHOR]

The present study introduces a novel approach for quantifying distances within constructed environments. A mathematical model was developed for distance estimation in image processing using width and height estimation. In order to determine distance, the study employed the use of visual angle and sky view factor (SVF). Additionally, a camera with capabilities similar to the human eye was utilized to capture 360-degree photographs from a fixed position within a virtual reality corridor. The technique of Sky View Factor (SVF) is employed in indoor environments with ceilings by eliminating windows, doors, and roofs, thereby simulating a virtual sky. This enables the calculation of various parameters such as the image's area, area fraction, and aspect ratio through the utilization of image processing methods. Distance estimation can be predicted through the utilization of the sky view factor and visual angle, employing a linear regression analysis. The method of virtual sky view factor (VSVF) has potential applications in the fields of Engineering, robotics, and architecture for the estimation of indoor distances. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic underscored the need for enhanced protective measures for healthcare workers, particularly surgeons, who face a heightened risk of exposure to infectious aerosols. However, conventional eye protection equipment such as face shields, goggles, or glasses often leads to ergonomic discomfort and a reduced field of view (FOV), impeding surgeons' ability to perform microsurgical procedures with precision and ease. To address these limitations, this study aimed to develop personalized 3D-printed eye gear for microscopic surgeons based on facial anthropometry data. 3D scanning was employed to obtain facial data from ten neurosurgery residents. Utilizing computer-aided designing, eye gears tailored to the unique facial features of each participant were developed. Finite element analysis-based contact simulation was used to assess the pressure exerted by the eye gear. Multi-material 3D printing was employed to fabricate the personalized eye gear. Participants, while donning the eye gear, engaged in simulation-based micro suturing tasks at various magnifications of the operating microscope, and marked the FOV range. They provided feedback scores (1–10) on the effectiveness of the eye gear through a Likert scale questionnaire (Q1-Q8). Finite element analysis demonstrated uniform strain distribution on the face, indicating that the edges of the customized eye gear fit exactly to the user's face. The average scores for the questionnaire Q1 to Q8 ranged from 6.8 to 8.5, with an overall mean score of 7.6. This indicates that the developed eye gear was simple to use and did not cause any discomfort. Additionally, the average reduction in the FOV was only 10.93% across the different operating microscope magnifications. These findings highlight eye gear's potential to alleviate discomfort and enhance precision in microscopic surgeries. Consequently, personalized 3D-printed eye gear offers a promising solution for providing surgeons with a safe environment while preserving the benefits of the operating microscope. [ABSTRACT FROM AUTHOR]

This research addresses the challenges of visually impaired individuals' independent travel by avoiding obstacles. The study proposes a distance estimation method for uncontrolled three-dimensional environments to aid navigation towards labeled target objects. Utilizing a monocular camera, the method captures cuboid objects (e.g., fences, pillars) for near-front distance estimation. A Field of View (FOV) model calculates the camera's angle and arbitrary pitch relative to the target Point of Interest (POI) within the image. Experimental results demonstrate the method's proficiency in detecting distances between objects and the source camera, employing the FOV and Point of View (POV) principles. The approach achieves a mean absolute percentage error (MAPE) of 6.18% and 6.24% on YOLOv4-tiny and YOLOv4, respectively, within 10 m. The distance model only contributes a maximum error of 4% due to POV simplification, affected by target object characteristics, height, and selected POV. The proposed distance estimation method shows promise in drone racing navigation, EV autopilot, and aiding visually impaired individuals. It offers valuable insights into dynamic 3D environment distance estimation, advancing computer vision and autonomous systems. [ABSTRACT FROM AUTHOR]

Abstract Omnidirectional photosensing is crucial in optoelectronic devices, enabling a wide field of view (wFoV) and leveraging potential applications for the Internet of Things in sensors, light fidelity, and photocommunication. The wFoV helps overcome the limitations of line‐of‐sight communication, and transparent photodetection becomes highly desirable as it enables the capture of optical information from various angles. Therefore, developing a photoelectric device with a 360° wFoV, ultra sensitivity to photons, power generation, and transparency is of utmost importance. This study utilizes a heterojunction of van der Waals SnS with Ga2O3 to fabricate a transparent photovoltaic (TPV) device showing a 360° wFoV with bifacial onsite power production. SnS/Ga2O3 heterojunction preparation consists of magnetron sputtering and is free from nanopatterning/nanostructuring to achieve the desired wFoV window device. The device exhibits a high average visible transmittance of 56%, generates identical power from bifacial illumination, and broadband fast photoresponse. Careful analysis of the device shows an ultra‐sensitive photoinduced defect‐modulated heterojunction and photocapacitance, revealed by the impedance spectroscopy, suggesting photon‐flux driven charge diffusion. Leveraging the wFoV operation, the TPV embedded visual and speech photocommunication prototype demonstrated, aiming to help visually and auditory impaired individuals, promising an environmental‐friendly sustainable future.

In the past three decades, laser warning systems (LWS) have emerged in great importance, as the development of laser-guided weapons, such as airborne Hellfire missiles, has increased, posing an imminent threat to vital areas and VIPs. The laser warning station (LWS) can detect, classify, identify, and give alarm from laser threat at a very short time with high sensitivity. Therefore, the designers of this system must take into account the detectability and field of view to cover the area to be secured. The main contribution in this research is an analytical design of LWS that consists of 24 detector elements, distributed in two arrays (2 × 12) circularly. Also, calculating the best distance between the detectors according to the laser beam spot size. In addition, enhancement laser warring sensor detection capability and detection performance FOV between the detectors to increase coverage area up to 360°. Moreover, decreasing dead zone area between the laser detectors element. Mathematical calculations and illustrations made to reach the best systematic design.

Objective To investigate the characteristics and objective assessment method of visual field defects caused by optic chiasm and its posterior visual pathway injury. Methods Typical cases of visual field defects caused by injuries to the optic chiasm, optic tracts, optic radiations, and visual cortex were selected. Visual field examinations, visual evoked potential （VEP） and multifocal visual evolved potential （mfVEP） measurements, craniocerebral CT/MRI, and retinal optical coherence tomography （OCT） were performed, respectively, and the aforementioned visual electrophysiological and neuroimaging indicators were analyzed comprehensively. Results The electrophysiological manifestations of visual field defects caused by optic chiasm injuries were bitemporal hemianopsia mfVEP abnormalities. The visual field defects caused by optic tract, optic radiation, and visual cortex injuries were all manifested homonymous hemianopsia mfVEP abnormalities contralateral to the lesion. Mild relative afferent pupil disorder （RAPD） and characteristic optic nerve atrophy were observed in hemianopsia patients with optic tract injuries, but not in patients with optic radiation or visual cortex injuries. Neuroimaging could provide morphological evidence of damages to the optic chiasm and its posterior visual pathway. Conclusion Visual field defects caused by optic chiasm, optic tract, optic radiation, and visual cortex injuries have their respective characteristics. The combined application of mfVEP and static visual field measurements, in combination with neuroimaging, can maximize the assessment of the location and degree of visual pathway damage, providing an effective scheme for the identification of such injuries.

The visual and non-visual effectiveness of light is often determined by measuring the spectrally weighed irradiance on the corneal plane. This is typically achieved using spectral irradiance or illuminance measurements, captured in a hemispheric (2π) geometry with a diffuser. However, the human binocular field of view (FOV) is not a perfect hemisphere, as it is occluded both upward and downward. Previous research on FOV-restricted measurements is limited, leaving the error from using hemispheric measurements for non-visual quantities undefined. In our study, we tackled this issue by designing and 3D printing FOV occlusions as attachments to spectral measurement devices. We took measurements with and without the occlusion in various laboratory (light from different directions) and real-world lighting situations (light typically from above). Our findings reveal a reduction of visual and melanopic values due to the FOV occlusion. These ranged from negligible to more than 60% in realistic scenarios. Interestingly, the reduction was consistent for both visual and melanopic parameters, as the distribution of light in the FOV was generally spectrally homogeneous. An exception occurred in a specific artificial laboratory situation, where the melanopic daylight (D65) efficacy ratio changed by more than a factor of 2 solely because of the FOV occlusion. Additionally, we observed that head orientation had a marked effect on all quantities measured. In conclusion, our results highlight the potential for substantial errors when solely relying on vertical, hemispheric measurements in experiments and non-visual lighting design projects. We encourage the (additional) use of FOV occlusion in eye-level measurements for typical viewing directions, and we are providing open-source 3D-print files to facilitate this practice.

Lensless fluorescence microscopy (LLFM) has emerged as a promising approach for biological imaging, offering a simplified, high-throughput, portable, and cost-effective substitute for conventional microscopy techniques by removing lenses in favor of directly recording fluorescent light on a digital sensor. However, there are several obstacles that this novel approach must overcome, such as restrictions on the resolution, field-of-view (FOV), signal-to-noise ratio (SNR), and multicolor-imaging capabilities. This review looks at the most current developments aimed at addressing these challenges and enhancing the performance of LLFM systems. To address these issues, computational techniques, such as deconvolution and compressive sensing, hardware modifications and structured illumination, customized filters, and the utilization of fiber-optic plates, have been implemented. Finally, this review emphasizes the numerous applications of LLFM in tissue analysis, pathogen detection, and cellular imaging, highlighting its adaptability and potential influence in a range of biomedical research and clinical diagnostic areas.

In this paper, a novel method is demonstrated to sustain vehicle-to-vehicle (V2V) communication on curvy roads via the arrangement of the lateral position of a self-angle-adjustable mirror–reflective road sign (SAAMRS) and light-direction-sensing wide-angle complementary photodiodes (CPDs). Visible light communication (VLC) between vehicles attracts attention as a complementary technology to radio-frequency-based (RF-based) communication technologies due to its wide, license-free spectrum and immunity to interferences. However, V2V VLC may be interrupted on curvy roads due to the limited field of view (FOV) of the receiver or the line of sight (LOS) being interrupted. To solve this problem, an experiment was developed using an SAAMRS along with wide-angle light-direction-sensing CPDs that used a precise peak detection (PPD) method to sustain communication between vehicles in dynamic environments by rerouting the incident light with the highest signal intensity level to the receiver vehicle on curvy roads. We also used real images of curvy roads simulated as polynomials to calculate the necessary rotation angles for the SAAMRS and regions where communication exist. Our experimental results overlapped almost completely with our simulations, with small errors of approximately 4.8% and 4.4% for the SAAMRS angle and communication region, respectively.

PURPOSEThe purpose of this study was to evaluate the effect of outside-field-of-view (FOV) lead shielding on the entrance surface dose (ESD) of the breast on an anthropomorphic X-ray phantom for a variety of axial skeleton X-ray examinations.METHODSUsing an anthropomorphic phantom and radiation dosimeter, the ESD of the breast was measured with and without outside-FOV shielding in anterior-posterior (AP) abdomen, AP cervical spine, occipitomental 30° (OM30) facial bones, AP lumbar spine, and lateral lumbar spine radiography. The effect of several exposure parameters, including a low milliampere-seconds technique, grid use, automatic exposure control use, wraparound lead (WAL) use, trolley use, and X-ray table use, on the ESD of the breast with and without outside-FOV shielding was investigated. The mean ESD (μSv) and standard deviation for each radiographic protocol were calculated. A one-tailed Student’s t-test was carried out to evaluate whether ESD to the breast was reduced with the use of outside-FOV shielding.RESULTSA total of 920 breast ESD measurements were recorded across the different protocol parameters. The largest decrease in mean ESD of the breast with outside-FOV shielding was 0.002 μSv (P = 0.084), recorded in the AP abdomen on the table with a grid, OM30 on the table with a grid, OM30 standard protocol on the trolley, and OM30 on the trolley with WAL protocols. This decrease was found to be statistically non-significant.CONCLUSIONThis study found no significant decrease in the ESD of the breast with the use of outside-FOV shielding for the AP abdomen, AP cervical spine, OM30 facial bones, AP lumbar spine, or lateral lumbar spine radiography across a range of protocols.

Risley-prism-based image sensors can expand the imaging field of view through beam control. The larger the top angle of the prism, the higher the magnification of the field of view, but at the same time, it aggravates the problem of imaging aberrations, which also puts higher requirements on the aberration correction method for the Risley-prism-based image sensor. To improve the speed, accuracy, and stability of the aberration correction process, an automatic calibration method for the Risley-prism-based image sensor is proposed based on a two-axis turntable. The image datasets of the calibration plate with different prism rotation angles and object distances are acquired using a two-axis turntable. Then, the images of the calibration plate are pre-processed using the bicubic interpolation algorithm. The calibration parameters are finally calculated, and parameter optimization is performed. The experimental results verify the feasibility of this automated calibration method. The reprojection error of the calibration is within 0.26 pixels when the distance of the imaging sensor is 3.6 m from the object, and the fine aberration correction results are observed. [ABSTRACT FROM AUTHOR]