Outdoor Lighting Research Articles

Selection of a Navigation Strategy According to Agricultural Scenarios and Sensor Data Integrity

In digital farming, the use of technology to increase agricultural production through automated tasks has recently integrated the development of AgBots for more reliable data collection using autonomous navigation. These AgBots are equipped with various sensors such as GNSS, cameras, and LiDAR, but these sensors can be prone to limitations such as low accuracy for under-canopy navigation with GNSS, sensitivity to outdoor lighting and platform vibration with cameras, and LiDAR occlusion issues. In order to address these limitations and ensure robust autonomous navigation, this paper presents a sensor selection methodology based on the identification of environmental conditions using sensor data. Through the extraction of features from GNSS, images, and point clouds, we are able to determine the feasibility of using each sensor and create a selection vector indicating its viability. Our results demonstrate that the proposed methodology effectively selects between the use of cameras or LiDAR within crops and GNSS outside of crops, at least 87% of the time. The main problem found is that, in the transition from inside to outside and from outside to inside the crop, GNSS features take 20 s to adapt. We compare a variety of classification algorithms in terms of performance and computational cost and the results show that our method has higher performance and lower computational cost. Overall, this methodology allows for the low-cost selection of the most suitable sensor for a given agricultural environment.

The Concept regarding Vehicular Communications Based on Visible Light Communication and the IoT

The most controversial technology—visible light communication—is becoming increasingly promising in the field of wireless networks, being ideal for many indoor and outdoor applications. This article proposes VLC methods and architectures capable of providing high security in vehicles and in their communications with the environment or other cars in traffic. The architectures proposed involve the inclusion of ambient lighting equipment and systems and indoor and outdoor lighting systems, such as headlights, traffic lights, and stoplights. Securing data within vehicular networks and validating them through multiple layers of filtering at the level of the physical PHY layer would drastically strengthen the position of VLC. They are the only source of information through which direct contact is maintained with the other entities in the network. The evaluations and proposals presented here are highly viable and deserve future consideration in light of the results obtained in the practical steps carried out in the research process.

Field‐based robotic leaf angle detection and characterization of maize plants using stereo vision and deep convolutional neural networks

AbstractMaize (Zea mays L.) is one of the three major cereal crops in the world. Leaf angle is an important architectural trait of crops due to its substantial role in light interception by the canopy and hence photosynthetic efficiency. Traditionally, leaf angle has been measured using a protractor, a process that is both slow and laborious. Efficiently measuring leaf angle under field conditions via imaging is challenging due to leaf density in the canopy and the resulting occlusions. However, advances in imaging technologies and machine learning have provided new tools for image acquisition and analysis that could be used to characterize leaf angle using three‐dimensional (3D) models of field‐grown plants. In this study, PhenoBot 3.0, a robotic vehicle designed to traverse between pairs of agronomically spaced rows of crops, was equipped with multiple tiers of PhenoStereo cameras to capture side‐view images of maize plants in the field. PhenoStereo is a customized stereo camera module with integrated strobe lighting for high‐speed stereoscopic image acquisition under variable outdoor lighting conditions. An automated image processing pipeline (AngleNet) was developed to measure leaf angles of nonoccluded leaves. In this pipeline, a novel representation form of leaf angle as a triplet of keypoints was proposed. The pipeline employs convolutional neural networks to detect each leaf angle in two‐dimensional images and 3D modeling approaches to extract quantitative data from reconstructed models. Satisfactory accuracies in terms of correlation coefficient (r) and mean absolute error (MAE) were achieved for leaf angle () and internode heights (). Our study demonstrates the feasibility of using stereo vision to investigate the distribution of leaf angles in maize under field conditions. The proposed system is an efficient alternative to traditional leaf angle phenotyping and thus could accelerate breeding for improved plant architecture.

Urban Park Lighting Quality Perception: An Immersive Virtual Reality Experiment

Green areas and parks are increasingly important in improving citizens’ physical and mental recovery. Lighting systems play a considerable role in affecting city park life and activities along with people’s moods and behavior in the evening and at night. Immersive virtual reality laboratory experiments may support urban and lighting research by providing information on the combination of lighting setup and visual context of existing or new urban parks. Gaze behaviors obtained from eye-tracking recordings and self-reported measurements using the perceived outdoor lighting quality questionnaire were used to determine the factors affecting human perception, comfort, and cognitive load, as the overall illuminance levels of the scene and correlated color temperature changes. Results pointed out that overall illuminance level and CCT significantly affect the perceived strength and comfort qualities of lighting with a dominance of the first compared with the latter when subjects were free to explore the lit environment. Low CCT and intermediate or high overall illuminance levels can improve the sense of accessibility as well as minimize the cognitive load.

Specifying Non-White Light Sources in Outdoor Applications to Reduce Light Pollution

ABSTRACT Anthropogenic (“human-generated”) light at night (ALAN) from outdoor lighting produces light pollution and as a result causes a range of deleterious responses in humans, plants, and animals. An emerging strategy to combat light pollution, especially sky glow, is to use “amber” LEDs in lieu of phosphor-converted white LEDs with high correlated color temperatures. Importantly, however, there is no standardized terminology or chromaticity designation that is applicable to “amber” LED lighting products for outdoor illumination. In this work, we propose a specification structure for light sources with nonstandard chromaticities to increase the precision of language used in the architectural lighting industry and demonstrate that light sources with well-defined chromaticity ranges outside of the ANSI C78.377–2017 quadrangles may be useful for reducing the portion of relative sky glow related to light source spectral power distribution. We encourage lighting standards development organizations to consider standardizing such a system.

From sodium-vapour to LEDs: how an outdoor lighting retrofit affects insects in Singapore

Abstract In the Anthropocene, the planet is warming and global biodiversity, including of insects, is being lost at an unprecedented rate. One largely urban sustainability solution, shifting to energy-efficient, light-emitting diode (LED) bulbs on outdoor lighting, has impacts on insects that are inadequately understood, especially in the tropics and brightly lit cities. Working in Singapore—a highly urbanised and light-polluted tropical city-state—we performed a field experiment to test the hypothesis that newly retrofitted LED lights are more attractive (i.e., detrimental) to insects compared to the high-pressure sodium (HPS) lamps they replace. Instead, our sticky traps, which we mounted on both light types, caught statistically equal numbers of arthropods (individuals and families). Traps on LED lamps also attracted proportionally fewer dipterans and more hemipterans and hymenopterans, but these effects were site-specific. Overall, we found no support for our hypothesis—our findings may reflect differential emissions of ultraviolet wavelengths by both light types and/or the possibility that urban insect assemblages with historic exposure to light pollution may not respond as expected to the retrofit. We caution against extrapolating findings from impact studies to untested contexts and highlight the need for (1) more studies in the rapidly urbanising tropics and (2) field tests of the effectiveness of measures to limit any negative ecological impacts of LED lighting, including other lethal and sublethal effects that we did not assess. We also discuss possible implications for ecosystem services and insect conservation.

A Novel Method to Prove the Visibility Distance of Candlelight and the Milky Way’s Vega Star and Apply this Knowledge to Outdoor Lighting Applications

A Novel Method to Prove the Visibility Distance of Candlelight and the Milky Way’s Vega Star and Apply this Knowledge to Outdoor Lighting Applications

STRUCTURAL DIAGRAM OF A SYSTEM FOR REMOTE MONITORING OF A HOUSEHOLD PLOT AND CONTROL OF ITS EQUIPMENT

Providing remote monitoring of homestead, suburban areas allows you to reduce the number of trips for their maintenance, to receive timely information about the overgrowth of the territory, the ripening of cultivated fruits, unauthorized visits to the site. The management of the site equipment makes it possible to monitor the watering of plants, turn on and off outdoor lighting, and perform other operations. Based on the analysis of existing solutions, their advantages and disadvantages, a block diagram of a system for remote monitoring of the territory of a household plot and management of its equipment has been developed. (Research purpose) The research purpose is developing a block diagram of a system for remote monitoring of a household plot and control of its equipment with the use of a photovoltaic installation. (Materials and methods) Analyzed literature sources, available methods and devices for monitoring household plots and managing their energy supply systems. We used general scientific methods, methods of developing structural schemes. (Results and discussion) We proposed the structure of a system for remote monitoring of the territory of a household plot and management of its equipment with the use of a photovoltaic installation in it, which allows for remote monitoring and management in automatic mode and using an application for a phone, computer. It was determined that the implementation of the structural scheme of the system allows to reduce the maintenance costs of the infield, increases the efficiency of its use. (Conclusions) It was revealed that the existing methods and technical means of remote monitoring of the territory of the household plot and management of its equipment are of a disparate nature and do not combine into a single system. We have developed a block diagram of a system for remote monitoring of the territory of a household plot and control of its equipment with the use of a photovoltaic installation in it. It was shown that new monitoring methods are being implemented in the system, a neural network is used to process the information received.

Guideline for Designing Rooftop Gardens in Amman Buildings

The aim of this study is to create a guideline for rooftop gardens in the city of Amman, taking into account the factors of social, environmental, and economic sustainability, and in a way that is largely consistent with the local building systems and regulations. Local libraries lack a guideline specialized in rooftop gardens, how to design and implement them, and choose the appropriate materials for them. The failure to exploit the unused rooftops of buildings in the city of Amman results in many environmental and architectural problems that this research found in order to address them, by providing diverse, accurate and standard information that facilitates the work of people interested in establishing rooftop gardens. To reach the desired goal of this research, many interviews were conducted with gardeners, experts and officials in companies with local and international sustainable products, in addition to experts in irrigation systems, monitoring and outdoor lighting. The information obtained by the researchers was tabulated through tables through which it is easy to access the information. The research outcomes are expected to develop design guidelines for the utilization of rooftop gardens in the city of Amman which respond to principles of sustainability, whether social, environmental or economical, as well as the result highlighted the importance of the guideline and the benefits that it can be brought to the city and its inhabitants from the environmental, social and even economic aspects.

Spatio-Temporal Outdoor Lighting Aggregation on Image Sequences Using Transformer Networks

In this work, we focus on outdoor lighting estimation by aggregating individual noisy estimates from images, exploiting the rich image information from wide-angle cameras and/or temporal image sequences. Photographs inherently encode information about the lighting of the scene in the form of shading and shadows. Recovering the lighting is an inverse rendering problem and as that ill-posed. Recent research based on deep neural networks has shown promising results for estimating light from a single image, but with shortcomings in robustness. We tackle this problem by combining lighting estimates from several image views sampled in the angular and temporal domains of an image sequence. For this task, we introduce a transformer architecture that is trained in an end-2-end fashion without any statistical post-processing as required by previous work. Thereby, we propose a positional encoding that takes into account camera alignment and ego-motion estimation to globally register the individual estimates when computing attention between visual words. We show that our method leads to improved lighting estimation while requiring fewer hyperparameters compared to the state of the art.

Modelling the Probability of Discomfort Due to Glare at All Levels: The Case of Outdoor Lighting

ABSTRACT To limit glare, lighting engineers need to estimate the level of discomfort produced by a lighting installation. Outdoor, most discomfort glare models predict a mean level of discomfort on a judgment scale, which corresponds to a “mean road user.” However, in real life, the inter-individual variability of the sensitivity to glare is large; predicting the mean discomfort does not describe the full pattern of responses in a population. We propose a methodology to model the Discomfort Level, computing the probabilities that an observer reports any of the levels of a discomfort scale. This methodology is demonstrated for outdoor lighting, where no probabilistic model is available. Using a dedicated psychophysical experiment, we extend the results of a previous study where a formula was proposed to compute the Glare Excitation due to a multi-source stimulus, at the Borderline between Comfort and Discomfort (BCD), with a background luminance consistent with outdoor lighting. This formula is first extended to other discomfort levels and background luminance levels, and strengthened thanks to a different experimental protocol and to the use of up to 10 glare sources simultaneously. From this experiment, a formula of the Glare Excitation is proposed in the range of outdoor lighting. Then, a probabilistic model of the Discomfort Level is proposed, allowing computing the probability of ratings at each level of an ordinal scale from the Glare Excitation computed with our formula. It is hoped that the proposed model avoids most of the modeling methodological caveats of previous discomfort glare models.

Features of Modeling the Operating Modes of Outdoor Lighting Lines

The necessity of modeling the operating modes of outdoor lighting lines with a voltage of 0.23/0.4 kV is substantiated. The choice of the optimal configuration of the lighting line while ensuring the standardized values of illumination and brightness on the working surface is recommended to be carried out by comparing several variants with different positions of pillars, types of light intensity curves, the number and power of luminaires. The results of the lighting calculation are the basis for modeling the electrical operation modes of outdoor lighting lines, which allows determining the operating parameters (node voltage, active and reactive power, current, voltage drop, loss of active and reactive power in individual sections). The obtained data can be used to select the cross-sectional area of conductor cores and forecast the power consumption of outdoor lighting, taking into account the specific features of light flux regulation (dimming). As a rule, outdoor lighting lines are connected to one power point. The use of outdoor lighting lines with bilateral supply for main streets and circular roads of relatively long length is proposed which will not only make it possible to increase the reliability of power supply of lighting installations, but also to use conductors with a smaller cross-section area of the cores. The electrical load of light sources is assumed on the basis of static characteristics. Modeling of the electrical modes of the outdoor lighting network is carried out taking into account the higher harmonics of current and voltage. The rational operation mode of the outdoor lighting line is determined by the magnitude of the voltage deviation from the nominal value, the indicators of non-sinusoidality and voltage asymmetry at the power supply point. Additional possibilities for modeling the modes of operation of lighting lines are to search for damage (detection of short circuits, determination of the presence of faulty lamps).

Controlling the artificial radiance of the night sky: The Añora urban laboratory

We provide radiometric evidence of the relevance of nearby light sources on the artificial brightness of the night sky. To obtain the required data we developed a method based on the use of power-regulated urban lighting systems, which also provides relevant information on the propagation of light pollution at short distances from the sources. A controlled experiment was carried out in the Andalusian municipality of Añora (1526 inhab.) in which the radiant power of its regulated public outdoor lighting system was modified in a predefined way during the central part of the night while continuously recording the zenith sky brightness in the TESS-W photometric band from two separate locations inside the town. We determined that the power-regulated streetlight sources contribute a 60–62% to the total zenith sky brightness at these observing locations in clear and moonless nights when operated at their maximum power rating, being the remaining sky radiance due to constant local sources and sources from neighboring towns. These results, in combination with georeferenced information on the sources' location and properties, impose some constraints on the functional form of the effective point-spread functions (PSF) of the zenith sky brightness at short distances from the sources. For the conditions of our experiment we have found that the expected exponents of power-law PSFs are close to -1.

The impact of lighting trespass on nearby buildings and their inhabitants which derives from municipal stadiums. Early results from a post occupancy evaluation survey

Outdoor lighting has a more significant environmental influence on flora and fauna than humans mainly because of the shortest time period that they may be spending outdoors. Yet, light trespass has an equally important influence on people since it may affect the living conditions in their everyday life, and consequently, their prosperity. The present study investigates houses with facades in front of municipal stadiums with no audience and affected by their lighting. The prevailing visual atmosphere caused by the lighting levels and its improper direction is definitely intrusive separating the indoor and outdoor environment. This anthropocentric research, conducted via the Post-Occupancy Evaluation (POE) methodology, aims to detect the visual and psychological effects and consequences of the visual surrounding caused by light pollution because of outdoor night lighting in an urban environment.

Synthesis and optical properties of Mn4+ activated double-perovskite niobate deep red phosphors for WLEDs and plant cultivation

Mn 4+ doped oxides red phosphors have great potential for white-light-emitting diodes (WLEDs) and plant growth light. Herein, deep red phosphors Ba 2 LuNbO 6 :xMn 4+ with perovskite structure were synthesized by solid state method in air atmosphere. The crystal structure, morphology, composition and optical properties of Ba 2 LuNbO 6 :Mn 4+ phosphors were systematically studied by X-ray diffraction, Rietveld refinement, SEM and EDS and photoluminescence spectra. Under excitation by 380 nm NUV light, the phosphor emitted bright red light around 670 nm and far-red light around 697 nm owing to the spin-forbidden 2 E g → 4 A 2g transition of Mn 4+ ions. Temperature-dependent photoluminescence spectra confirmed the high thermal stability of Mn 4+ -activated Ba 2 LuNbO 6 phosphors. The fluorescence intensity maintained about half of the initial intensity at 400 K, and the thermal quenching was due to the increase of non-radiative transitions at high temperature. Finally, LED devices were fabricated using 365 nm NUV chips with commercial blue, green phosphors and Ba 2 LuNbO 6 :Mn 4+ red phosphors for the use of outdoor lighting, which had color rendering index (CRI) of 84.4 and color temperature (CCT) of 5710 K. The results indicate that Ba 2 LuNbO 6 :Mn 4+ phosphors have great potential as a deep red phosphor in the field of WLEDs and plant growth light. • Deep red phosphor Ba 2 LuNbO 6 :Mn 4+ were prepared by high temperature solid state method in air atmosphere for WLEDs and plant cultivation. • The Ba 2 LuNbO 6 :Mn 4+ phosphor presents deep red emission from 650 nm to 720 nm. • Ba 2 LuNbO 6 :Mn 4+ phosphors have excellent photoelectric performance for LED application.

Impact of Solid State Roadway Lighting on Melatonin in Humans.

In 2009, the World Health Organization identified vehicle crashes, both injury-related and fatal, as a public health hazard. Roadway lighting has long been used to reduce crashes and improve the safety of all road users. Ocular light exposure at night can suppress melatonin levels in humans. At sufficient light levels, all visible light wavelengths can elicit this response, but melatonin suppression is maximally sensitive to visible short wavelength light. With the conversion of roadway lighting to solid state sources that have a greater short wavelength spectrum than traditional sources, there is a potential negative health impact through suppressed melatonin levels to roadway users and those living close to the roadway. This paper presents data on the impact of outdoor roadway lighting on salivary melatonin in three cohorts of participants: drivers, pedestrians, and those experiencing light trespass in their homes. In an outdoor naturalistic roadway environment, healthy participants (N = 29) each being assigned to a cohort of either pedestrian, driver, or light trespass experiment, were exposed to five different solid state light sources with differing spectral emissions and one no lighting condition. Salivary melatonin measurements were made under an average roadway luminance of 1.0 cd/m2 (IES RP-18 Roadway Lighting Requirements for expressway roads) with a corneal melanopic Equivalent Daylight Illuminances (EDI) ranging from 0.22 to 0.86 lux. The results indicate that compared to the no roadway lighting condition, the roadway light source spectral content did not significantly impact salivary melatonin levels in the participants in any of the cohorts. These data show that recommended levels of street lighting for expressway roads do not elicit an acute suppression of salivary melatonin and suggest that the health benefit of roadway lighting for traffic safety is not compromised by an acute effect on salivary melatonin.

Long-Time Trends in Night Sky Brightness and Ageing of SQM Radiometers

A very wide-used instrument for the measurement of the Night Sky Brightness (NSB) is the Sky Quality Meter (SQM). One of its important issues is tracking NSB for long time and connecting its variations to changes in outdoor lighting. The stability of these radiometers is fundamental; variation on the instrument behaviour could be confused with changes of the sky brightness. The SQMs of the network of the Veneto Region (Italy) and the SQM installed at La Silla (Chile) are analysed by using the twilight method considering both sunset and dawn measurements, which allows to compensate for shifts in the SQM internal clock. The slope of the observed long-term trends ranges between 29 ± 5 and 86 ± 22 mmagSQM arcsec−2 year−1. These high values require a correction of the measurements to continue to track NSB by those instruments. The correction is presented for an Italian site, for example: raw measures show an apparent trend towards darker sky (30 ± 5 mmagSQM arcsec−2 year−1), after the correction a clear tendency towards a brighter polluted sky appears (−21 ± 8 mmagSQM arcsec−2 year−1), in agreement with the estimated trend of the installed luminous flux of outdoor lighting for that area.

Study on the importance of upgrading public lighting systems

The paper presents a case study which advocates for the adoption of smart outdoor illumination installations that come with energy management systems. To analyse the energy efficiency we carried out measurements on: a) a classical outdoor lighting system, with sodium vapour sources, b) the same system after the sodium vapour light sources were replaced with LEDs, and c) the same system with LEDs augmented with an energy management system. Our analysis shows that replacing the outdoor light-sources with LEDs, in combination with an energy management system, results in a reduction of 40% in energy consumption. At the same time, the luminance coefficients of the LED lighting system are significantly higher than the luminance coefficients of sodium vapour sources.

Technical Guidance Provision in Electricity Energy Saving for Teachers and Educational Staff of SDN 09 Pontianak Timur

The provision of electricity is crucial, so efficiency must be done because electrical energy is a top priority for residential, industrial, and outdoor lights. All tiers of society must support the government's efforts to ensure the stability of the nation's energy supply through initiatives to boost supply and conserve energy. The public, particularly the lower middle class, do not yet understand the existing technology well; the information of its benefits and drawbacks have not been equally spread. Energy researchers and experts assert that the domestic or household sector's contribution to the attempt to cut power usage is very significant due to the comparatively high share of residential consumers. A project must be carried out to provide counseling in the form of instruction on cost savings when utilizing electrical and electronic gadgets in homes and schools. The counseling results revealed that the teachers of SDN 09 Pontianak Timur were genuinely interested in what they were hearing and in the presented curriculum. Through the counseling technique it is observed that the community is becoming more conscious of the need to utilize electrical energy more intelligently and is gaining new insights into how to do so. These insights help the community promoting energy efficiency in daily life.

Social interaction in local public squares after dark

This paper explores social interaction in local public squares under different lighting conditions. At its best public squares are social spaces that engender a sense of belonging, increase the quality of life and wellbeing of individuals. It is proposed that outdoor lighting would be essential to the use of the public realm after dark, but empirical results regarding lighting conditions and social aspects of life in public squares are limited. Based on a socio-physical conceptual model of the transactional relationship of the user, the lit environment and the behavioural outcome, this study investigated active social interaction in daylight compared to after dark. A field study was conducted in two local public squares in Malmö, Sweden. The occurrences of which visitors were being alone, in pairs, or in groups of three or more (N=2522), and verbal or non-verbal interaction amongst those in company of another person were recorded. The lit appearance of the two squares after dark, was assessed with HDR-photography and photometric measurements; portraying dissimilar spatial, spectral and intensity characteristics. The results of social interaction show dissimilar patterns of the two squares; an increase in social interaction in EL after dark was observed in one of the squares, while a decrease in the afternoon and no significant difference was displayed in the evening after dark in the other square. It is suggested that lighting may sustain patterns of social interaction after dark, however it might be, that the company of another is especially important after dark.