Multiple Angle Observations Would Benefit Visible Band Remote Sensing Using Night Lights

The spatial and angular emission patterns of artificial and natural light emitted, scattered, and reflected from the Earth at night are far more complex than those for scattered and reflected solar radiation during daytime. In this commentary, we use examples to show that there is additional information contained in the angular distribution of emitted light. We argue that this information could be used to improve existing remote sensing retrievals based on night lights, and in some cases could make entirely new remote sensing analyses possible. This work will be challenging, so we hope this article will encourage researchers and funding agencies to pursue further study of how multi‐angle views can be analyzed or acquired

Commentary: Multiple Angle Observations Would Benefit Visible Band Remote Sensing using Night Lights

The spatial and angular emission patterns of artificial and natural light emitted, scattered, and reflected from the Earth at night are far more complex than those for scattered and reflected solar radiation during daytime. In this commentary, we use examples to show that there is additional information contained in the angular distribution of emitted light. We argue that this information could be used to improve existing remote sensing retrievals based on night lights, and in some cases could make entirely new remote sensing analyses possible. This work will be challenging, so we hope this article will encourage researchers and funding agencies to pursue further study of how multi-angle views can be analyzed or acquired

Development of a dynamic system for capturing and processing digital images for the real-time determination of the photometric parameters of road and tunnel lighting installations

This research deals with the development of a dedicated system for the measurement of road surface luminance and the assessment of road and tunnel lighting systems in real time. The system is designed to be installed on a moving vehicle in order to avoid disturbance of vehicle traffic and to minimize the required time of the measurements.According to the current standards on lighting measurements on roads and tunnels, the assessment of the lighting levels is mandatory for safety reasons and should be repeated at regular intervals throughout the lifetime of the installation. This is reinforced by the need for the rational use of energy in highly energy-intensive street and tunnel lighting installations.The equipment, that is traditionally used for such kind of measurements, presents major issues concerning the time needed for the measurements, the field preparation and post processing effort. Even modern systems using digital optical sensors are designed, in particular, for laboratory measurements by limiting their usability to external test fields. In any case, measurements on roads and tunnels require a partial or total interruption of vehicle traffic, which put at risk the road safety and increases the complexity of the whole operation.The road surface luminance measurement system was developed based on CCD technology and specialized image processing techniques. The equipment is installed on a vehicle, the measurements are carried out as the vehicle moves, and the measurement results can be exported in real time. The development of the system is related to the design and implementation of both devices and software algorithms for the purpose of dynamic lighting measurements on roads and tunnels. Specific calibration and testing apparatuses for each individual subsystems have been developed. At the same time, the corresponding measurement methodologies were designed and described for each type of measurement.This text also includes the presentation of analytical test results of the system in real operating conditions through measurements in tunnels and open road sections.Η παρούσα διατριβή αφορά στην ανάπτυξη ενός ολοκληρωμένου συστήματος μέτρησης λαμπρότητας οδοστρώματος και αξιολόγησης του συστήματος φωτισμού οδών και οδικών σηράγγων σε πραγματικό χρόνο. Το σύστημα έχει σχεδιασθεί ώστε να εγκαθίσταται επί κινουμένου οχήματος με στόχο την αποφυγή όχλησης της κυκλοφορίας των οχημάτων και την ελαχιστοποίηση του απαιτούμενου χρόνου εκτέλεσης των μετρήσεων.Σύμφωνα με τα ισχύοντα πρότυπα, τα οποία αφορούν τις μετρήσεις φωτισμού σε οδούς και σήραγγες, η αξιολόγηση των επιτευχθέντων επιπέδων φωτισμού καθίσταται αναγκαία για λόγους ασφαλείας και θα πρέπει να επαναλαμβάνεται σε τακτά χρονικά διαστήματα καθ’ όλη τη διάρκεια ζωής της εγκατάστασης. Αυτό ενισχύεται και από την ανάγκη για την ορθολογική χρήση της ενέργειας στις ιδιαίτερα ενεργοβόρες εγκαταστάσεις φωτισμού οδών και σηράγγων.Ο εξοπλισμός που χρησιμοποιείται για τις εν λόγω μετρήσεις παρουσιάζει σημαντικά προβλήματα στο χρόνο ολοκλήρωσης των μετρήσεων, την προετοιμασία του πεδίου και την μετέπειτα επεξεργασία. Ακόμη και τα σύγχρονα συστήματα που χρησιμοποιούν ψηφιακούς οπτικούς αισθητήρες είναι σχεδιασμένα, κυρίως, για εργαστηριακές μετρήσεις περιορίζοντας τη χρηστικότητά τους σε εξωτερικά πεδία δοκιμών και μετρήσεων. Σε κάθε περίπτωση, οι μετρήσεις σε οδούς και σήραγγες επιβάλλουν μερική ή ολική διακοπή της κυκλοφορίας των οχημάτων, γεγονός που θέτει σε κίνδυνο την οδική ασφάλεια και αυξάνει την πολυπλοκότητα του όλου εγχειρήματος.Το σύστημα μέτρησης λαμπρότητας οδοστρώματος που αναπτύχθηκε βασίζεται στην τεχνολογία των ψηφιακών οπτικών αισθητήρων - CCD - και σε εξειδικευμένες τεχνικές επεξεργασίας εικόνας. Ο εξοπλισμός εγκαθίσταται σε όχημα, οι μετρήσεις εκτελούνται καθώς το όχημα κινείται, ενώ τα αποτελέσματα των μετρήσεων δύναται να εξαχθούν και σε πραγματικό χρόνο. Η ανάπτυξη του συστήματος αφορά στο σχεδιασμό και την υλοποίηση τόσο των συσκευών όσο και των αλγορίθμων λογισμικού για το σκοπό της εκτέλεσης δυναμικών μετρήσεων φωτισμού σε οδούς και σήραγγες. Αναπτύχθηκαν ειδικές διατάξεις βαθμονόμησης και δοκιμών των επιμέρους υπο-συστημάτων. Παράλληλα σχεδιάσθηκαν και περιγράφονται οι αντίστοιχες μεθοδολογίες μετρήσεων για κάθε τύπο μέτρησης. Στο κείμενο περιλαμβάνεται, επίσης, παρουσίαση αναλυτικών αποτελεσμάτων δοκιμών του συστήματος σε πραγματικές συνθήκες λειτουργίας μέσω μετρήσεων σε σήραγγες και τμήματα ανοικτής οδοποιίας

Simulations and Analysis of the Optimum Uniformity for Pedestrian Road Lighting Focusing on Energy Performance and Spill Light in the Roadside Environment

Road lighting uniformity is an essential lighting quality parameter for motorists and pedestrians and varies with lighting design parameters. Increased road lighting uniformity may result in benefits, such as increased reassurance and perceived safety for pedestrians or an increased overall visual perception. However, no previous study has investigated how road lighting uniformity varies with lighting design scenarios or how the uniformity of various lighting design scenarios affects other essential parameters, such as energy performance and obtrusive light. This study aimed to investigate: (I) how uniformity varies with different road lighting design scenarios, and (II) how uniformity correlates with energy performance and risk for increasing spill light. The study is limited to pedestrian roads. We performed photometric calculations in ReluxDesktop for more than 1.5 million cases with single-sided pole arrangements and for various geometries of road width, pole distance, pole height, overhang, and luminaire tilt. The results were analyzed with a set of five relevant metrics that were calculated and analyzed together with uniformity. For the evaluation, we used the minimum luminaire power needed to achieve an average illuminance of 10 lx, the power density indicator (DP), edge illuminance ratio (REI), and we introduced two new indicators for spill light on the ground in the border areas: the extended edge illuminance ratio (extended REI) and the spill flux ratio (RSF). The results show that increased uniformity levels may significantly increase energy consumption and spill light, but that both these impacts can be relatively controlled if uniformity is kept under certain limits. The investigated cases also demonstrated that improper lighting planning significantly increases adverse effects, such as spill light

Waveforms for the validation of calculated temporal light modulation metrics.:MetTLM 20NRM01 - D1

This report describes a set of waveforms for verification purposes and other calculations relating to temporal light modulation (TLM). The waveforms are intended to be used in comparisons of software implementations and for estimating measurement uncertainty from modelled effects as well as other calculation-based studies of TLM. The report gives TLM metric values of PstLM and SVM, these are calculated from various implementations of the TLM metric algorithms. The results show standard deviations, all under 0.04 for both metrics, except one outlier. Furthermore, the report gives examples of how estimation of measurement uncertainty can be derived from applying various effects that can be modelled and applied to the waveforms. This is used to study the effect on the resulting metrics. Specific guidance is given towards using the examples to reach measurement uncertainties under 0.05 for both PstLM and SVM. The waveforms are stored in a permanent repository, for referencing and comparing results across platforms. This report is part of the output from the EMPIR project MetTLM Metrology of Temporal Light Modulation (20NRM01). For more information see the project website mettlm.eu

Simulations and Analysis of the Optimum Uniformity for Pedestrian Road Lighting Focusing on Energy Performance and Spill Light in the Roadside Environment

Road lighting uniformity is an essential lighting quality parameter for motorists and pedestrians and varies with lighting design parameters. Increased road lighting uniformity may result in benefits, such as increased reassurance and perceived safety for pedestrians or an increased overall visual perception. However, no previous study has investigated how road lighting uniformity varies with lighting design scenarios or how the uniformity of various lighting design scenarios affects other essential parameters, such as energy performance and obtrusive light. This study aimed to investigate: (I) how uniformity varies with different road lighting design scenarios, and (II) how uniformity correlates with energy performance and risk for increasing spill light. The study is limited to pedestrian roads. We performed photometric calculations in ReluxDesktop for more than 1.5 million cases with single-sided pole arrangements and for various geometries of road width, pole distance, pole height, overhang, and luminaire tilt. The results were analyzed with a set of five relevant metrics that were calculated and analyzed together with uniformity. For the evaluation, we used the minimum luminaire power needed to achieve an average illuminance of 10 lx, the power density indicator (DP), edge illuminance ratio (REI), and we introduced two new indicators for spill light on the ground in the border areas: the extended edge illuminance ratio (extended REI) and the spill flux ratio (RSF). The results show that increased uniformity levels may significantly increase energy consumption and spill light, but that both these impacts can be relatively controlled if uniformity is kept under certain limits. The investigated cases also demonstrated that improper lighting planning significantly increases adverse effects, such as spill light

Ecological Impact of Artificial Light at Night: Effective Strategies and Measures to Deal with Protected Species and Habitats

When conserving or protecting rare or endangered species, current general guidelines for reducing light pollution might not suffice to ensure long-term threatened species’ survival. Many protected areas are exposed to artificial light at levels with the potential to induce ecological impacts with unknown implications for the ecosystems they are designated to protect. Consequently, it is recommended that precautionary methods for the avoidance and mitigation of light pollution in protected areas be integrated into their management plans. This paper’s aims are to present an overview of best practices in precautionary methods to avoid and mitigate light pollution in protected areas and to identify and discuss what ecosystems should be considered light-sensitive and how to prioritise species and habitats that need protection from artificial light, including examples of legislation covering ecological light pollution in the European Union and in Sweden. The important aspects to include when considering light pollution at a landscape level are listed, and a proposal for prioritisation among species and habitats is suggested. Sensitive and conservation areas and important habitats for particularly vulnerable species could be prioritised for measures to minimise artificial lighting’s negative effects on biodiversity. This may be done by classifying protected natural environments into different zones and applying more constrained principles to limit lighting. The light pollution sensitivity of various environments and ecosystems suggests that different mitigation strategies and adaptations should be used depending on landscape characteristics, species sensitivity and other factors that may determine whether artificial light may be detrimental. Issues of the currently used measurement methods for artificial light at night are reviewed. We also propose and discuss the principles and benefits of using standardized measurement methods and appropriate instrumentation for field measurements of artificial light concerning the environmental impact of light pollution

Low Cost Automation System for Smart Houses based on PIC Microcontrollers

International audienceThe high electricity bills of houses have triggered a significant research for solutions to mitigate this issue. The house automation systems offer everything necessary to put an end to these inconveniences as, most often, they incorporate a number of smart devices (microcontrollers and sensors). The presented work outlines the development of a microcontroller-based automation system of a solar smart house using automatic lighting and thermal comfort sensors (temperature, humidity) and safety functions (gas leakage, smoke detection). This system is based on PIC microcontrollers and is applied through the implementation of a complete algorithm. The program is written on Micro C, and in order to realize the control circuit and the simulation, the testing software made use of Proteus software which is freely available from the Internet. The control of temperature and air pollution was implemented using the PIC16F877A, while the light control was applied with the PIC18F4550. The hardware prototype was also provided to experiment on the designed control strategy. The results of this work allowed some conclusions to be reached and confirmed the benefits of this kind of automation systems

Illuminating the future of wearable light metrology : Overview of the MeLiDos Project

Light exposure profoundly influences human health, regulating circadian rhythms and impacting wakefulness and sleepiness. Estimating the effects of light exposure under everyday conditions requires personal, wearable light logging and dosimetry approaches. This article introduces the MeLiDos Project (2023–2026), supported by the European Association of National Metrology Institutes (EURAMET). The project’s first branch defines quality indices and calibration standards for wearable light loggers, adapting existing metrological standards to their smaller size and distinct purpose in the field rather than the laboratory. The second branch develops a software ecosystem, including the open-source R software package LightLogR, designed to manage the increasing volume of data, ensuring reusability, accessibility and interoperability of data. The third branch explores the potential of spatially resolved light dosimetry. The MeLiDos Project anticipates advancements in wearable light metrology, paving the way for optimizing human health and well-being through wearable light logging technologies. The project (22NRM05 MeLiDos) has received funding from the European Partnership on Metrology, co-financed by the European Union’s Horizon Europe Research and Innovation Programme and by the Participating States.</p