Target Illumination Research Articles

Enhancing Small Target Detection in Aerial Imagery with Bi-PAN-FPN and EDMOA-Optimized YOLOv8-s

Across the globe, people are working to build "smart cities" that will employ technology to make people's lives better and safer. Installing cameras at strategic spots across the city to monitor public spaces besides provide real-time footage to law enforcement besides other local authorities is a crucial part of smart city infrastructure, which includes video surveillance. A more effective answer is provided by deep learning algorithms, however research in this area still faces significant problems from changes in target size, form change, occlusion, and illumination circumstances as seen from the drone's perspective. In light of the aforementioned issues, this study presents a highly effective and resilient approach for aerial picture identification. To begin, the concept of Bi-PAN-FPN is presented to enhance the neck component of YOLOv8-s, taking into consideration the prevalent issue of small targets being easily misdetected or ignored in aerial photos. We achieve a more advanced and thorough feature fusion procedure much as feasible by completely considering and reusing multiscale features. To further reduce the amount of parameters in the model and prevent info loss during long-distance feature transfer, the benchmark model's backbone incorporates the GhostblockV2 structure in lieu of a portion of the C2f module. With the help of the Enhanced Dwarf Mongoose Optimization Algorithm (EDMOA), the suggested model's hyper-parameters are optimised. Lastly, a dynamic nonmonotonic focusing mechanism is employed in conjunction with WiseIoU loss as bounding box regression loss. The detector accounts for varying anchor box quality by utilizing "outlier" evaluations, thus improving the complete presentation of the detection task.

Wide-field optical tracking of LEO objects: Theoretical assessment and observing strategy

The main technical and strategic aspects related to Space Surveillance and Tracking (SST) with optical sensors are set in context in this study to lead to an efficient inventory of the active satellites and un-cooperant space debris population at Low-Earth orbital regimes (LEO). In particular, special emphasis is devoted to the combined interplay between timing of observations, target illumination conditions, instrumental fine tuning and data acquisition mode (surveying vs. active tracking).At LEO altitudes, satellites are seen to cross the sky at very high angular velocity, in excess to 0.5–1.5 deg/sec, always making their positional measurements (and the inferred dynamical properties) a challenging task for ground telescopes. To this aim, objective criteria have to be identified for a best trade-off between instrument field of viev (FOV), CCD/CMOS platescale, telescope aperture and exposure time in order to maximize target(s) detection and reference grid of stars valuable for astrometry. Many counter-intuitive aspects are discussed in this regard, compared for instance with a more classical “astronomical” approach, delving in particular the widely recognized inherent link between time-tag accuracy and resolving power of optical imagery to track LEO objects.A number of tables and graphical plots are provided for practical use to the reader.

TIN-X version 3: update with expanded dataset and modernized architecture for enhanced illumination of understudied targets.

TIN-X (Target Importance and Novelty eXplorer) is an interactive visualization tool for illuminating associations between diseases and potential drug targets and is publicly available at newdrugtargets.org. TIN-X uses natural language processing to identify disease and protein mentions within PubMed content using previously published tools for named entity recognition (NER) of gene/protein and disease names. Target data is obtained from the Target Central Resource Database (TCRD). Two important metrics, novelty and importance, are computed from this data and when plotted as log(importance) vs. log(novelty), aid the user in visually exploring the novelty of drug targets and their associated importance to diseases. TIN-X Version 3.0 has been significantly improved with an expanded dataset, modernized architecture including a REST API, and an improved user interface (UI). The dataset has been expanded to include not only PubMed publication titles and abstracts, but also full-text articles when available. This results in approximately 9-fold more target/disease associations compared to previous versions of TIN-X. Additionally, the TIN-X database containing this expanded dataset is now hosted in the cloud via Amazon RDS. Recent enhancements to the UI focuses on making it more intuitive for users to find diseases or drug targets of interest while providing a new, sortable table-view mode to accompany the existing plot-view mode. UI improvements also help the user browse the associated PubMed publications to explore and understand the basis of TIN-X's predicted association between a specific disease and a target of interest. While implementing these upgrades, computational resources are balanced between the webserver and the user's web browser to achieve adequate performance while accommodating the expanded dataset. Together, these advances aim to extend the duration that users can benefit from TIN-X while providing both an expanded dataset and new features that researchers can use to better illuminate understudied proteins.

BCLA CLEAR Presbyopia: Evaluation and diagnosis

It is important to be able to measure the range of clear focus in clinical practice to advise on presbyopia correction techniques and to optimise the correction power. Both subjective and objective techniques are necessary: subjective techniques (such as patient reported outcome questionnaires and defocus curves) assess the impact of presbyopia on a patient and how the combination of residual objective accommodation and their natural DoF work for them; objective techniques (such as autorefraction, corneal topography and lens imaging) allow the clinician to understand how well a technique is working optically and whether it is the right choice or how adjustments can be made to optimise performance. Techniques to assess visual performance and adverse effects must be carefully conducted to gain a reliable end-point, considering the target size, contrast and illumination. Objective techniques are generally more reliable, can help to explain unexpected subjective results and imaging can be a powerful communication tool with patients. A clear diagnosis, excluding factors such as binocular vision issues or digital eye strain that can also cause similar symptoms, is critical for the patient to understand and adapt to presbyopia. Some corrective options are more permanent, such as implanted inlays / intraocular lenses or laser refractive surgery, so the optics can be trialled with contact lenses in advance (including differences between the eyes) to better communicate with the patient how the optics will work for them so they can make an informed choice.

Research on Optical System of Dim Target Simulator Based on Polarization Stray Light Suppression

In view of the lack of high-precision optical simulation equipment for dim space targets at present, in this study, a simulation method for dim space targets based on polarization stray light suppression is proposed, the overall optical system architecture of the optical engine for depolarization stray light suppression is constructed, the mechanism of stray light generation is explored, and the dark state light leakage suppression method is presented by compensating the phase of LCOS reflected light with wave plate; a high-image quality collimating optical system with large field of view and flat aberration is designed based on the illumination system optimization method of the critical angle matching of the spectroscopic film; and the polarization stray light suppression effect and star position simulation error of the dim target simulator are tested. The test results show that the illumination of the simulated dim target is ≮10−10 lx, the contrast is 6.96, the non-uniformity of the bright state is only 5.88%, and the simulation error of the star position is 9.9″. This research can make some contributions to enhancing the observability of detecting dim targets, breaking through the detection technology of extremely dark targets in space, developing advanced deep space detection capabilities, and improving the engineering technology system of deep space exploration.

Feasibility Study of Using 5G Signals for Illumination Purposes in Passive Radar

Feasibility Study of Using 5G Signals for Illumination Purposes in Passive Radar

TRP drop, TRP drop: a steady patter of anti-schistosomal target illumination

Infections caused by parasitic flatworms impart a significant disease burden. This is well exemplified by the neglected tropical disease schistosomiasis, which afflicts millions of people worldwide. The anti-schistosomal activity of various chemotypes has been known for decades, but the parasite targets of many of these remain undefined. Until recently, this included the current clinical therapy, praziquantel (PZQ). However, the tempo of target discovery has recently gathered pace, with discoveries of schistosome targets for praziquantel (PZQ) and the anthelmintic benzodiazepine, meclonazepam (MCLZ). This steady patter of target illumination has also revealed a pattern in that both PZQ and MCLZ target members of the same ion channel subgroup—transient receptor potential ion channels of the melastatin family (TRPM channels). PZQ activates one member of this family (TRPMPZQ) and MCLZ activates a different channel (TRPMMCLZ). Here, similarities and differences between these two new targets are discussed. These data highlight the need for further study of TRPM channels in parasitic flatworms given their vulnerability to chemotherapeutic attack.

A Proposal for A Human-in-the-Loop Daylight Control System—Preliminary Experimental Results

Appropriate daylight control could maximize occupants’ visual comfort, potentially saving energy. However, the deployment of daylight control systems (DLCSs) is not happening, mainly due to the complex system calibration and the frequent reluctance of occupants toward automatic control systems that exclude their participation. In this paper, a human-in-the-loop DLCS is presented. The system is designed to allow the users to have direct interaction via smartphone Bluetooth communication, enabling them to set the lighting values deemed most comfortable nimbly. Special attention has been paid to the power consumption of the DLCS, especially in standby mode. Accessibility of configuration has been taken into consideration, leading to the choice of a wireless configured device. The performance of the prototype DLCS was evaluated experimentally in a side-lit room and compared with that of a commercial controller. The illuminance on a reference work plane was measured during the operation of the systems to observe the controllers’ effect on the lamp’s luminous flux while simultaneously considering the variation of daylight conditions. Moreover, the energy performance of the systems was studied to obtain information about the energetic effectiveness and convenience of the studied DLCSs. The main results showed that the proposed system could maintain the required target illuminance values on the work plane as daylight conditions vary: the maximum deviation measured using the prototype never exceeded 11 lx. In comparison, the commercial controller reached peaks of 220 lx. Moreover, the energy consumption of the prototype (resulting equal to 370 mVA) was lower than the consumption of the commercial system (equal to 600 mVA), allowing for increased energy savings over the long period. The more straightforward configuration allows the user to better interact with the DLCS.

Mirrorless MEMS imaging: a nonlinear vibrational approach utilizing aerosol-jetted PZT-actuated fiber MEMS scanner for microscale illumination.

This study introduces a novel image capture and lighting techniques using a cutting-edge hybrid MEMS scanner system designed for compact microscopic imaging. The scanner comprises a tapered optical fiber waveguide and innovative aerosol-jet printed PZT (lead zirconate titanate) bimorph push-pull actuators on a stainless-steel substrate, effectively addressing issues that are commonly associated with PZT on silicon substrates such as fracture and layer separation. By leveraging nonlinear vibration, the scanner achieves a spiral scan pattern from a single signal input, in addition to the expected two-dimensional scanning and target illumination from two phase-shifted inputs. This capability is further enhanced by a novel process to taper the optical fiber, which reduces illumination scattering and tunes the fiber to the resonant frequencies of the scanner. The precisely tapered tip enables large fields of view while maintaining independent 2-axis scanning through one-degree-of-freedom actuation. Experimental validation showcases the successful generation of a spiral scan pattern with a 60 μm diameter scan area and a 10 Hz frame rate, effectively reconstructing scanned images of 5 μm lines, cross patterns (15 μm in length with a 5 μm gap), and structures of a Psychodidae wing.

A Computationally Efficient Beamforming Solution for Bistatic RF Sensing with RIS-Enhanced Target Illumination

A Computationally Efficient Beamforming Solution for Bistatic RF Sensing with RIS-Enhanced Target Illumination

Transparent Dual-Frequency CMUT Arrays for Photoacoustic Imaging.

The opaque ultrasound transducers used in conventional photoacoustic imaging systems necessitate oblique light delivery, which gives rise to some disadvantages such as inefficient target illumination and bulky system size. This work proposes a transparent capacitive micromachined ultrasound transducer (CMUT) linear array with dual-band operation for through-illumination photoacoustic imaging. Fabricated using an adhesive wafer bonding method, the array consists of optically transparent conductors [indium tin oxide (ITO)] as both top and bottom electrodes, a transparent polymer [bisbenzocyclobutene (BCB)] as the sidewall and adhesive material, and largely transparent silicon nitride as the membrane. The fabricated device had a maximum optical transparency of 76.8% in the visible range. Furthermore, to simultaneously maintain higher spatial resolution and deeper imaging depth, this dual-frequency array consists of low- and high-frequency channels with 4.2- and 9.3-MHz center frequencies, respectively, which are configured in an interlaced architecture to minimize the grating lobes in the receive point spread function (PSF). With a wider bandwidth compared to the single-frequency case, the fabricated transparent dual-frequency CMUT array was used in through-illumination photoacoustic imaging of wire targets demonstrating an improved spatial resolution and imaging depth.

The refractive behaviour of the human eye under different ambient lighting conditions

Background: Adjustment of the ocular accommodative system is an important phenomenon allowing for optimal vision at different distances.Aim: The study compared the refractive behaviour of the human eye under different ambient lighting conditions for different target brightness.Setting: Auto-refraction measurements were taken of the participants in the Department of Optometry at the University of Johannesburg.Methods: Five African participants from a single ethnic group aged between 20 years and 25 years, had 40 successive auto-refractor (Nidek AR 610) measurements taken on the right eye of each participant in a bright and dark room using the illuminated and dark targets (LL and DL); dark target in the illuminated and dark room (LD and DD).Results: A change in the refractive state of all participants was observed on LL and LD, except for one, who experienced myopic shifts. The largest significant difference in the variance-covariances and the means was approximately 2.40 dioptre (D). The other participants’ shifts in means were approximately the same and varied between 1.00 D and 1.50 D stigmatic shift. For the DL to DD conditions all participants, except for one, underwent a hyperopic shift of about 0.50 D.Conclusion: The refractive behaviour of the human eye appears to be dependent on ambient light conditions as well as target illumination or luminance.Contribution: The study is scientific and clinical, and focuses on changes in refractive behaviour under different lighting conditions, falling within the scope of the journal. Key insights are that there is a change in the refractive behaviour of the eye under different ambient conditions.

Underwater power compensated white light source based on synthetic white laser

The semiconductor white laser light source is used as a light source for underwater illumination. The required standard color temperature of white light is obtained at the underwater target surface. We studied the power compensation of a synthetic white laser source and its application to underwater illumination. First, the power ratios of the red (638 nm), green (520 nm), and blue (450 nm) lasers at a color temperature of 6500 K were obtained by using chromaticity theory. Next, the three-color and synthetic white laser parameters were obtained with transmission distance, according to the exponential attenuation characteristics of different light in clear water and seawater medium. The three-color laser power at the output was compensated, and the underwater target illumination surface reached the standard 6500 K color temperature of the white laser, improving the illumination. Finally, an experimental system for underwater white laser illumination based on power compensation was established. The errors between experimental and theoretical results of color temperature and illuminance are no more than 0.43% and 22.15%. This power-compensated synthetic white laser light source has both the advantages of long-range underwater detection and the spectral advantages of LED white light sources. The white laser light source meets specific requirements by compensating for power and optimizing white light characteristics for underwater lighting applications.

Low-loss tunable beam collimator and expander assembly with no moving parts using anengineered diffuser and varifocal lenses.

In this paper, we present a novel design for a tunable beam collimator. A variable collimator assists in achieving an adaptive size of an output collimated beam. Alternatively, it can also provide an adjustable output beam divergence angle for a noncollimated beam output. Tunable collimators are highly desirable for various applications in testing, engineering, and measurements. Such devices are also useful in providing tunable illumination of samples or targets in microscopes and emulating different target distances for characterizing the performance of camera systems in laboratory settings. The proposed collimator has two distinct advantages: it is light-efficient compared with pinhole-based collimator designs, and it delivers a large range of output beam sizes without involving the mechanical motion of bulk components. These attributes are achieved via the use of an engineered diffuser (in the place of a pinhole) and a pair of large aperture tunable focus lenses, which deliver a tunable magnification to the output collimated beam. In laboratory experiments, we achieve an optical transmission efficiency of 90% for the proposed tunable collimator.

Raw Data Simulation of Spaceborne Synthetic Aperture Radar with Accurate Range Model

Simulated raw data have become an essential tool for testing and assessing system parameters and imaging performance due to the high cost and limited availability of real raw data from spaceborne synthetic aperture radar (SAR). However, with increasing resolution and higher orbit altitudes, existing simulation methods fail to generate SAR simulated raw data that closely resemble real raw data. This is due to approximations such as curved orbits, “stop-and-go” assumption, and Earth’s rotation, among other factors. To overcome these challenges, this paper presents an accurate range model with a “nonstop-and-go” configuration for raw data simulation based on existing time-domain simulation methods. We model the SAR echo signal and establish a precise space geometry for spaceborne SAR. Additionally, we precisely identify the target illumination area based on elliptical beams through space coordinate transformation. Finally, the SAR raw data were accurately simulated using high-precision time-domain simulation methods. The accuracy of the proposed model was validated by comparing it with the traditional hyperbolic model and the curved orbit model with “stop-and-go” assumption through image processing of the generated raw data. Through the analysis of point target quality parameters, the errors of various parameters in our distance model compared with the other two models are within 1%. Furthermore, this simulation method can be adapted to simulate raw data of other modes and satellite orbits by adjusting beam control and satellite orbit parameters, respectively. The proposed simulation method demonstrated high accuracy and versatility, thereby providing a valuable contribution to the development of remote sensing technology.

UAV-Based Bistatic SAR-Imaging Using a Stationary Repeater

Synthetic aperture radar (SAR) is an established technique for high-resolution radar imaging relying on the ego-motion of the radar. The long coherent integration time of the radar in conjunction with a linear or circular trajectory enables the illumination of targets under different observation angles leading to robustness against short-time interference signals. The use of a bistatic setup to simultaneously acquire multiple observation angles further increases the aforementioned benefits. In this work, a bistatic SAR system using an active repeater is proposed, in the following called Bistatic Repeater-SAR (BR-SAR). In BR-SAR the repeater acts as a second observer providing a bistatic path with low system cost and hardware effort. This article discusses the BR-SAR approach with all signal processing and hardware considerations necessary to build the bistatic radar system. This includes a description of the full system and signal chain with a focus on the signal separation and evaluation of both monostatic and bistatic signals and the subsequent SAR processing. The approach is verified via simulations and measurements, in which conventional SAR is compared to the proposed BR-SAR system. Hardware effects leading to a deteriorated system performance of the bistatic system are analyzed and countermeasures are discussed and implemented. Finally, the benefits of the bistatic system are demonstrated based on a realistic measurement scenario.

MATHEMATICAL ASPECTS OF DETERMINING THE MOTION PARAMETERS OF A TARGET BY UAV

Research relevance When performing reconnaissance missions, a UAV system primarily conducts surveillance of the target area, locates stationary or moving enemy targets, determines their coordinates or transmits their images directly to the command post. Directing artillery fire as well as guiding missiles or carrying out target designation (illumination of targets) for high-precision weapons, automatic determination of target coordinates and their prompt transmission to the appropriate ground stations is essential. This article provides a mathematical solution to the issue of determining the motion parameters of a target spotted during surveillance of an area by a reconnaissance drone (UAV). The subject of the study in the article is UAV- rocket-artillery systems. The purpose of the work is to develop a mathematical model for determining the parameters of the target's movement using a UAV. The following tasks are solved in the article: to develop target positioning diagram; to develop a mathematical model for determining the parameters of the target's movement. The methods used in the article are the methods of mathematical modelling. The following results were obtained: а target positioning scheme has been compiled to determine the coordinates and movement parameters; a mathematical dependence has been developed to determine the coordinates of a fixed target; a mathematical model has been developed to determine the parameters of the target's movement. Conclusions: by calculating the current coordinates of a moving target using the method proposed in this paper, it is possible to determine the coordinates of the target and parameters of the target's movement, including the direction of movement and the trajectory.

A Study on Daylight Performance Evaluation in Primary School Classrooms

From the early beginning of construction in history, priority of using daylight has played an active role in the settlement decision, building shape and façade design. Today, the necessity of conscious consumption has become an accepted fact due to the depletion of energy resources. For this reason, the effective use of daylight and reducing lighting energy consumption have become one of the most important goals of today's architecture. 
 The purpose of the natural lighting system is providing sufficient daylight to the target area, considering the visual comfort conditions. Nowadays, for the architectural design of buildings, the use of passive systems is primarily preferred in terms of energy efficiency. The use of natural lighting as a passive system, minimizing building lighting energy requirements and creating the desired visual environment should be prioritized in terms of providing visual comfort. In educational buildings, it is vital to design a lighting system in which daylight is used effectively in order to meet the visual needs of the instructors and students and to minimize the usage of lighting energy. Within the scope of the TS EN 17037 standard, which was developed for daylight assessment in buildings and approved by CEN on 29.07.2018 and lastly updated on 02.03.2022, the criteria for daylight assessment is handled under 4 headings: daylight provision, view out, exposure to sunlight and protection from glare. For each criteria specified in indoor daylight assessment, three grades are defined as 'minimum, medium and high'.
 In this study, the criterion of providing daylight in educational buildings was examined in accordance with the TS EN 17037 standard. With the study, it is aimed to develop an approach to determine the optimum values ​​of the parameters of direction, obstacle presence and transparency ratio in the context of providing sufficient daylight in the primary classroom design. Investigated building type is the primary school building classroom, which was created in optimum dimensions according to the characteristics of primary education classrooms defined in the ‘Educational Buildings Minimum Design Standards Guide’ published by the Ministry of National Education. It is aimed to evaluate and develop the criteria given in the ‘Educational Buildings Minimum Design Standards Guide’ according to the TS EN 17037 standard, which defines daylight performance in Turkey. The classroom model discussed within the scope of the study has been modeled with the Rhino program according to the alternative transparency rates and obstacle situations; In the simulation, the Climate Studio plugin, which was developed for the calculation of dynamic evaluation parameters, was used. The area handled by using evaluation methods according to the 17037 standard included in the software was evaluated in terms of annual daylight performance. The availability of target illuminance levels in half of the daylight hours throughout the year was calculated using the daylight autonomy method, and the climatic data of the province of Istanbul were used as a representative in the calculations. The results obtained were evaluated according to the TS EN 17037 Daylight Standard, and the scenarios created were classified as 'minimum, medium and high' according to the availability of daylight. According to this classification, optimum transparency ratio, window direction and obstacle conditions conditions for the city of Istanbul in primary school classroom design are discussed. The optimal transparency ratios for each aspect are discussed. The minimum transparency ratio values ​​given in the ‘Educational Buildings Minimum Design Standards Guide’ were compared with the optimum transparency ratios obtained.
 
 
 Keywords: Daylight Performance, TS EN 17037, Primary school classrooms, Window Design

Indoor illuminance selection procedure using fuzzy techniques

The current practice of selecting target illuminance based on the recommendations of the Illuminating Engineering Society has serious shortcomings. For example, the visual age of the observer has precise boundaries, the illuminance values are exact instead of an acceptable range, and the sudden increase of illuminance values with age is rather arbitrary. To come up with an exact output from an input that is, by its very nature, uncertain and imprecise is virtually impossible. The aim of this work is to develop an approach that overcomes the limitations of the current illuminance selection method. This work proposes an alternative method for illuminance selection based on Fuzzy techniques. Fuzzy techniques are approximations used to model phenomena or decisions for which mathematical precision is impractical. The vagueness and uncertainties of many lighting design variables suit Fuzzy logic modeling, whereby a crisp output can be obtained from a range of Fuzzy input variables. The new method involves visual age, task difficulty and task importance as input variables which lead to a target illuminance. The target illuminance is given the name “Fuzzy Illuminance” (FILL). A MATLAB digital application was developed and can be used by lighting designers. It is expected that the proposed technique and the digital application will not only resolve the limitations of the current illuminance selection procedure but will also simplify the process of the selection of illuminance design targets and on-site verification of such design targets.

Design and Application of Phase-Only Diffractive Optical Element Based on Non-Iterative Method

In this study, we devised a method for the design of continuous phase-only holographic masks that map laser light to arbitrary target illumination patterns, which have a wide range of applications. In this method, the discrete gradient of a holographic mask is obtained by combining geometric optics and the linear assignment problem (LAP) methods, and then the entire problem is transformed into an integral problem with a discrete gradient. Finally, the least squares method is used to solve the gradient integral to complete the construction of a phase holographic mask. Due to its good continuity, this mask design method can also be applied to the production of diffractive optical elements. We discussed the effectiveness of this method by constructing two holographic masks with uniform illumination. At the same time, we successfully constructed an Einstein face holographic mask with non-uniform illumination using the LAP method for the first time. It is believed that this method can be widely used in illumination mode, ion capture and other directions.