Daylight Conditions Research Articles

Thermal Comfort in a Greened Office Building: Investigation and Evaluation through Measurement and Survey

The productivity, health, and well-being of office workers are known to be influenced by the indoor thermal conditions, most significantly the temperature and air humidity. This article is based on measurements and calculated predictions, as well as surveys of the employees in a newly renovated office building in Vienna, Austria. The renovation measures include street-side facade greening. The aim of this study was to determine the possible effects these renovation measures have on thermal comfort inside the building. The evaluation is carried out in accordance with the standards based on the predicted mean vote (PMV), calculated with the collected measurement data. Based on the survey, the calculation results are compared with the subjective perception of the employees. Even though the measurements and the survey were carried out only one year after the renovation, about 70% of the employees’ statements speak about noticeable positive changes due to the renovation measures. Regarding daylight and artificial lighting conditions, a total of 80% of employees are neutral or satisfied. The majority also expresses neutrality or satisfaction regarding spatial conditions and air quality. The satisfaction of the employees is reflected in their work performance. The goal is therefore to achieve the highest possible satisfaction of the building’s users.

Dynamic Lighting and Natural Ventilation in Patient Rooms at New Psychiatry Bispebjerg

This paper presents preliminary results of analyzes of the indoor environmental quality (IEQ) in a full scale rotatable 1:1 mockup of a patient room. As initial part of the planning of the indoor environment at a new mental hospital, the project seeks to uncover the natural differences and limitations of the building, caused by the geographical orientation. Examining the outdoor diurnal variations and their effect on the indoor environment, in order to create a balance between on the one hand, daylight and artificial lighting and on the other hand the demand for passive cooling, using natural ventilation. The analysis discuss potential health aspects of daylight and fresh air and proposes a new strategy for dynamic artificial lighting, including natural ventilation to supplement mechanical ventilation. In this article we uncover daylight conditions based on two main parameters; 1) the geographic orientation (N, S, E and W) and 2) the season (summer and winter). Based on the preliminary data and the regional daylight conditions, the article proposes a new way to plan the indoor environmental quality called Lattitude and Orientation Compensated Architectural Lighting (LOCAL).

Window geometry and its effect on the experience of illuminated spaces – a study of three daylit architectural cases

Looking at the architecture of modern housing in Denmark, it seems to express an understanding that equals more daylight with good daylight. With coated energy glass, the windows have increased in size, making glass into a façade material. This means that windows are no longer just holes in the façade but rather make up the entire façade itself. This changes the spatial relationship between the window design and distribution of daylight within the interior space, though we seldom address this lacking a vocabulary and methods. This paper sets out to investigate and experiment with how we can describe and document this change in daylight conditions and how these influence our visual environment, using photographs to record this. The methodology focusses on observations of daylit spaces in three different housing examples in Copenhagen from the 1800s to today. By observing the three daylit spaces, it becomes clear that differences in the size, shape, and position of window apertures influence the qualities of light in a space significantly. Considering that when it comes to window apertures different designs affect the experience of light in a space significantly, it is important to take this into account when designing with daylight. It is also important from a sustainability point of view to include this awareness in future design approaches.

First Implementation of a Normalized Hotspot Index on Himawari-8 and GOES-R Data for the Active Volcanoes Monitoring: Results and Future Developments

The Advanced Himawari Imager (AHI) and Advanced Baseline Imager (ABI), respectively aboard Himawari-8 and GOES-R geostationary satellites, are two important instruments for the near-real time monitoring of active volcanoes in the Eastern Asia/Western Pacific region and the Pacific Ring of Fire. In this work, we use for the first time AHI and ABI data, at 10 min temporal resolution, to assess the behavior of a Normalized Hotspot Index (NHI) in presence of active lava flows/lakes, at Krakatau (Indonesia), Ambrym (Vanuatu) and Kilauea (HI, USA) volcanoes. Results show that the index, which is used operationally to map hot targets through the Multispectral Instrument (MSI) and the Operational Land Imager (OLI), is sensitive to high-temperature features even when short-wave infrared (SWIR) data at 2 km spatial resolution are analyzed. On the other hand, thresholds should be tailored to those data to better discriminate thermal anomalies from the background in daylight conditions. In this context, the multi-temporal analysis of NHI may enable an efficient identification of high-temperature targets without using fixed thresholds. This approach could be exported to SWIR data from the Flexible Combined Imager (FCI) instrument aboard the next Meteosat Third Generation (MTG) satellites.

Rechargeable Potent Anti‐Viral Cotton Grafted with a New Quaternized N‐Chloramine

AbstractPolymeric substrates can be endowed with antiviral properties by grafting N‐chloramine precursors to the surface. These surfaces bind oxidative chlorine from a dilute chlorine bleach solution and are similarly recharged after depletion for reuse. Previously, enhanced antibacterial efficacy of quaternized N‐chloramines compared to their neutral counterparts is reported. In this study, a new quaternized N‐chloramine N1‐(3‐methacrylamidopropyl)‐N1,N1,N10,N10‐tetramethyl‐N10‐(2,2,6,6‐tetramethylpiperidin‐4‐yl)decane‐1,10‐diaminium (MAMPIP) featuring two quaternary ammonium groups within the structure to boost the chlorination efficiency and achieve excellent antiviral efficacy against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is reported. Antiviral fabrics are prepared by free‐radical graft polymerization of MAMPIP, or copolymerization of MAMPIP with a comonomer (acrylamide or methacrylamide) onto cotton fabrics to achieve enhanced durability to re‐chlorination. The poly(MAMPIP) grafted cotton, after chlorination, is highly effective against SARS‐CoV‐2 and achieves 4.59 log reduction (99.997%) after 5 min contact. Samples grafted with the copolymer of MAMPIP and acrylamide or methacrylamide are resistant to hydrolysis during re‐chlorination and retain high active chlorine and antiviral activity after 5 cycles of re‐chlorination (>3 log reduction after 10 min contact). Furthermore, the N‐chloramine coatings show excellent stability after exposure to simulated daylight conditions under an accelerated weathering tester, and storage for 200 days at 21 °C, 65% RH. The resulting quaternized N‐chloramine grafted cotton is a suitable platform for reusable antiviral textiles.

Experimental study on the impact of double tilted Venetian blinds on indoor daylight conditions

One of the most important concerns when designing buildings as liveable spaces is the indoor comfort. This depends on different factors, including daylight availability and discomfort glare conditions.The increasing use of glazing areas in the building's envelopes can lead to high energy consumption and problems such as visual discomfort. The use of shading devices stands out as a sustainable design strategy to reduce energy consumption in the buildings. This work presents an experimental analysis of the impact of an innovative shading device, a double-tilted venetian blind (DTVB) with different positions of upper and lower slats, on the indoor daylight conditions. Moreover, discomfort glare evaluation, through DGPs metric, is performed.The experimental campaign was conducted in an outdoor test cell during three periods of the year: summer solstice, winter solstice and autumn equinox. Experiments were carried out with both white and grey DTVBs, for several positions of upper and lower slats, under clear and overcast sky conditions. This comprises the measurement of indoor and outdoor horizontal and vertical illuminances and irradiances and solar and visible transmittance of the fenestration. It was concluded that DTVBs can achieve a higher performance, regarding solar protection, daylighting and glare control, when compared with more traditional venetian blinds systems.

A radiative cooling paper based on ceramic fiber for thermal management of human head

The intensification of global warming has resulted in extremely hot weather in many parts of the world, posing a severe challenge to the health and safety of outdoor workers. Passive daytime radiative cooling (PDRC) textiles with no energy input requirements can effectively achieve temperature management. However, few wearable radiative cooling devices have been successfully prepared. This study demonstrates a radiative cooling paper (RCP) with tunable stiffness for the thermal management of human head by using SiO 2 fibers and fumed SiO 2 as emitters. The as-prepared RCP exhibits high sunlight reflectivity of 0.97, and high emissivity of 0.91 in the atmospheric window. The results demonstrate that the RCP hat can prevent hair from overheating by reducing the temperature by an average of 12.9 °C compared with a white cotton hat under peak daylight conditions. Besides, the RCP exhibits outstanding integrated properties of high mechanical properties, waterproofness, and air permeability. Therefore, it is more suitable than other textiles for the manufacture of radiative cooling hats, and offers a promising solution to solve the problem of head thermal management in outdoor conditions. • This study designed and prepared a ceramic fiber paper with remarkable passive daytime radiative cooling performance. • The radiative cooling paper (RCP) exhibits good impact strength, superhydrophobicity, and air permeability. • The RCP is suitable for the manufacture of radiative cooling hat to achieve the thermal management of human head.

Evidence for human-centric in-vehicle lighting: Part 2-Modeling illumination based on color-opponents.

Illumination preference models are usually defined in a static scenery, rating common-colored objects by a single scale or semantic differentials. Recently, it was reported that two to three illumination characteristics are necessary to define a high correlation in a bright office-like environment. However, white-light illumination preferences for vehicle-occupants in a dynamic semi- to full automated modern driving context are missing. Here we conducted a global free access online survey using VR engines to create 360° sRGB static in-vehicle sceneries. A total of 164 participants from China and Europe answered three levels in our self-hosted questionnaire by using mobile access devices. First, the absolute perceptional difference should be defined by a variation of CCT for 3,000, 4,500, and 6,000 K or combinations, and light distribution, either in a spot- or spatial way. Second, psychological light attributes should be associated with the same illumination and scenery settings. Finally, we created four driving environments with varying external levels of interest and time of the day. We identified three key results: (1) Four illumination groups could be classified by applying nMDS. (2) Combinations of mixed CCTs and spatial light distributions outperformed compared single light settings (p < 0.05), suggesting that also during daylight conditions artificial light supplements are necessary. (3) By an image transformation in the IPT and CAM16 color appearance space, comparing external and in-vehicle scenery, individual illumination working areas for each driving scenery could be identified, especially in the dimension of chroma-, partially following the Hunt-Effect, and lightness contrast, which synchronizes the internal and external brightness level. We classified our results as a starting point, which we intend to prove in a follow-up-controlled laboratory study with real object arrangements. Also, by applying novel methods to display high fidelity 360° rendered images on mobile access devices, our approach can be used in the future interdisciplinary research since high computational mobile devices with advanced equipped sensory systems are the new standard of our daily life.

Use of DSLR and Sonic Cameras to Detect and Locate High-Voltage Corona Discharges.

Corona discharges are a concern in high-voltage applications. It is of utmost importance to detect and locate the discharges at an early stage using simple methods for this purpose. This paper evaluates and compares the sensitivity of two methods for detecting and locating the source of discharges, which are based on a digital single-lens reflex (DSLR) camera and a portable wideband sonic camera incorporating a matrix of micro-electromechanical systems (MEMS) microphones. Both cameras can generate an image of the studied area where the discharge sites are identified. The study is carried out with different electrode geometries, 50 Hz alternating current (ac) and positive and negative direct current (dc) supplies, and the effect of the distance between the sensor and the discharge sites is also analyzed. The presented results show that the sonic camera enables fast, simple, and sensitive detection and localization of the source of corona discharges even at a very early stage in daylight conditions, regardless of the type of power supply, that is, ac or positive/negative dc, and at distance of several meters from the discharge source.

Validation of spectral simulation tools in the context of ipRGC-influenced light responses of building occupants

With the growing awareness about ipRGC-influenced light (IIL) responses, design applications related to these responses are flourishing. To compare design options and optimize lighting conditions for building occupants, lighting simulations are typically used. However, as our IIL responses depend on the spectral characteristics of light, spectral simulations are required. The goal of this study is to validate two spectral simulation tools, ALFA and Lark, for the study of indoor spaces in relation to occupants’ IIL responses. Indicators associated with IIL responses derived from ALFA- and Lark-simulated data are compared against indicators derived from data measured under indoor daylighting and electric lighting conditions. The results show that Lark outperforms ALFA in most cases, with a simulation error in the ±20% range for point-in-time indicators. When accounting for time dynamics of light exposure, at least 9% of the daylight exposures simulated for a 6-h period in Lark lead to a significant error.

Laser Ranging Bathymetry Using a Photon-Number-Resolving Detector

The sensitivity and robustness against background noise of optical measurements, and specifically range-finding, can be improved by detecting the light with photon-number-resolving detectors (PNRD). We use a PNRD to detect single pulse reflections from the seabed level in the presence of high attenuation of the sea water. Measurements are performed from above the sea level, overcoming broad daylight conditions. We demonstrate continuous measurement of the seabed depth up to around 24 m, using laser pulse energies of 10 μJ, while sailing at speed of 2.2 knots. Additionally, we use these data to extract values of the refractive index and optical attenuation in coastal seawater. The method could be used as a novel and optically-accurate bathymetry tool for coastal research and underwater sensing applications.

Assessing the applicability of the European standard EN 17037:2018 for office spaces in a cold climate

There is a lack of methods and studies that evaluate the validity of daylight standards such as the EN 17037:2018 in specific local contexts as cold climates. Moreover, the probable adaptation of the EN 17037:2018 by European countries motivated the aim of this investigation: to study the applicability of the EN 17037:2018 in a certain cultural context through the comparison of the subjective perception of Estonian office users with the quantitative assessment defined by the EN 17037:2018, including the four aspects: solar access, view out, daylight provision, and glare protection. In order to study the applicability of the EN 17037:2018 for Estonian office spaces, we used a mixed-method approach based on semi-structured interviews, measurements, and daylight simulations. Poor view out is related with high obstruction levels of urban features, despite the presence of multiple layers in the view. The level of recommendations for good view out in Estonian office rooms might be lower than the thresholds recommended by the EN 17037:2018. Except during winter months, direct sunlight exposure is not appreciated in Estonian office spaces since it is strongly related to glare discomfort caused by sun in the field of view and on computer screens. Working under daylight conditions during the whole year and having an easy-to-use interior shading systems to block the direct sunlight is very valuable for Estonian office users. For daylight and glare protection, there is a good agreement between qualitative evaluations given by office users and quantitative assessments proposed by the EN 17037:2018.

Detection performance improvement method of single-photon LiDAR by the combination of speckle suppression with adaptive adjustment of aperture diameter and spatial correlation method

The flash array imaging LiDAR with the laser transmitted by the multimode fiber (MMF), will get a low detection performance which is caused by the severe transmitting light field's speckle and high-noise intensity in the daylight condition. In this paper, a scheme of the combination of speckle suppression with adaptive adjustment of aperture diameter (AAAD) and spatial correlation method is proposed to improve the detection performance. In which the speckle suppression by vibrating the MMF with the optimal vibration parameters can effectively suppress the speckle, and the AAAD can help to get the optimal triggering probability, besides, the spatial correlation method can increase the detection number and suppress the speckle in a further step. Firstly, the proposed scheme is built based on the speckle suppression and single-photon triggering probability model. Secondly, the proposed scheme is verified by the theoretical analysis, and it can effectively improve the detection performance under the low SNR condition. Finally, the experimental verification under the high-noise intensity condition is carried out, and the speckle contrast is reduced from 1.247 to 0.057, which is decreased by 95.4%; the target recovery ratio or signal detection probability is increased from 28.8% to 97.7%, which is improved by 239.2%. This work is useful for the effective detection of the laser MMF coupling transmitted single-photon LiDAR under daylight conditions.

Improved photocatalytic disinfection of dual oxidation state (dos)-Ni/g–C3N4 under indoor daylight

This work reports the antibacterial application of the dual oxidation state of nickel on g-C3N4 (dos-Nickel/g-C3N4) nanocomposite. The nanocomposite is prepared through simple wet impregnation assisted pyrolysis technique, and is characterized by standard techniques. Different geometries of nickel (spherical, and hexagonal disc) are decorated on the graphitic-carbon nitride surface examined through HR-TEM imagery. Photoluminescence of the synthesized nanocomposite can achieve better charge separation due to the quenching effect. The photocatalytic disinfection of dos-Ni/g-C3N4 nanocomposite is evaluated using E. coli as a model pathogen under normal indoor daylight. Selective dosage of nickel in the nanocomposite showed 100 % photocatalytic destruction efficiency of E. coli compared to g–C3N4, under shorter irradiation time. The photocatalytic disinfection mechanism is interrogated with various scavengers, and it is determined that superoxide (·O2–), and hole (h+) are the crucial radicals participating in the disinfection destructive mechanism. Taken together, this research presents the fabrication of dos-Ni/g-C3N4 nanocomposite, and its potential application to bioenvironmental remediation under normal indoor daylight conditions.

Epistemic Uncertainties in the Assessment of Regional Soil Acidification

The increasing acidification of soil due to pollution and agricultural management practices is a growing problem worldwide, where food production is already under threat by climate change, more frequent droughts, and soil nutrient depletion. Soil acidification is quantified by pH measurements and is a primary metric for soil health. High soil acidity is a constraint on the production of grains and other crops because it decreases the bioavailability of important plant nutrients while increasing soil toxicity arising from an imbalance of essential soil elements. Field pH can be estimated by colour test kits which are very cost-effective and particularly suitable for developing countries where laboratory services are not available or fail to provide timely results. Because the pH test kit is based on visual colour matching between a colour card scale and a soil sample in solution, there are epistemic uncertainties, such as variability in expert opinion, differences in colour vision, measurement error, instrumentation, and changes in daylight spectral content. In this study, expert human observers were compared in experiments conducted using a standard pH test kit under a range of environmental conditions. A significant difference in uncertainty in colour discrimination was evident between male and female experts, whereas changes in daylight conditions had lower impact on the variance of pH estimates. In a group of subject matter experts, the male standard error (0.35 pH) was 57% higher on average over the range of pH values (pH = 4 → 10) compared to females (0.22 pH). This error was largest (70%) in the low pH 4 to 6.5 range, which is a critical range for successful amelioration of soil acidification. The results suggest that historical database measurements may have hitherto unrecognised uncertainties that affect confidence intervals for experimental data that in turn will have an impact on predictive models and policy development.

Experimental evaluation of louver guidance efficiency for green sturgeon (Acipenser medirostris)

AbstractThroughout the world, louver‐bypass systems are a common method for fish protection at water diversion sites. Their performance has been evaluated for pelagic, strong‐swimming teleost fishes, but limited information exists regarding the effectiveness of louvers for guiding sturgeon, despite being a globally threatened taxon. This study used controlled laboratory experiments to quantify louver efficiency for juvenile green sturgeon under a range of conditions. Fish guidance efficiency was influenced most strongly by fish size and approach velocity, with poor efficiency for small fish at high velocities. Low velocities and, to a lesser extent, daylight conditions allowed a greater proportion of fish to remain upstream of the louver at all sizes. High velocities resulted in the greatest contact rate between the sturgeon and louver face. Louvers can be effective for benthic, weak‐swimming fish, but site‐ and species‐specific needs should always be considered in the development or operation of a louver guidance system.

Artificial light at night promotes bottom-up changes in a woodland food chain

Artificial light at night (ALAN) is a recognised disruptor of biological function and ecological communities. Despite increasing research effort, we know little regarding the effect of ALAN on woody plants, including trees, or its indirect effects on their colonising invertebrates. These effects have the potential to disrupt woodland food webs by decreasing the productivity of invertebrates and their secretions, including honeydew and lerps, with cascading effects on other fauna. Here, we cultivated juvenile river red gums (Eucalyptus camaldulensis) for 40 weeks under experimentally manipulated light (ALAN) or naturally dark (control) conditions. To assess direct impacts on tree growth, we took multiple measures of growth at four time periods, and also measured physiological function, biomass and investment in semi-mature trees. To assess experimentally the direct and indirect (tree-mediated) impacts of ALAN on invertebrates, from 19 weeks onwards, we matched and mismatched trees with their original ALAN environments. We colonised trees with a common herbivore of E. camaldulensis, the red gum lerp psyllid (Glycaspis nr. brimblecombei) and then measured the effects of current and historic tree lighting treatment on the psyllid life cycle. Our data revealed direct effects of ALAN on tree morphology: E. camaldulensis trees exposed to ALAN shifted biomass allocation away from roots and into leaves and increased specific leaf area. However, while the intensity of ALAN was sufficient to promote photosynthesis (net carbon gain) at night, this did not translate into variation in tree water status or photosystem adaptation to dim night-time light for ALAN-exposed trees. We found some evidence that ALAN had broad-scale community effects—psyllid nymphs colonising ALAN trees produced more lerps—but we found no other direct or indirect impacts of ALAN on the psyllid life cycle. Our results suggest that trees exposed to ALAN may share morphological responses with trees under dim daylight conditions. Further, ALAN may have significant ‘bottom-up’ effects on Eucalyptus woodland food webs through both trees and herbivores, which may impact higher trophic levels including woodland birds, mammals and invertebrates.

Effects of short daylight and mild low temperature on mitochondrial degeneration in the testis of Cricetulus barabensis.

In this study, we investigated the mitochondrial energy supply capacity and molecular mechanisms of apoptosis, mitochondrial fission, and mitophagy in regulating mitochondrial degeneration in testis of striped dwarf hamsters (Cricetulus barabensis) under mild low temperature (15°C) and short daylight (10 h:14 h) conditions. Results showed that under moderate daylight and mild low temperature (ML), short daylight and moderate temperature (SM), short daylight and mild low temperature (SL) conditions, the mitochondria were swollen and cristae were disrupted. Compared with the moderate daylight & moderate temperaturegroup (MM; 12 h:12 h, 22°C), the number of mitochondria was significantly decreased in the SMandSL groups. Both short daylight and mild low temperature reduced the protein expression of citrate synthase, thus the energy supply capacity of mitochondria may be weakened. Compared with the MM group, bax/bcl2 protein expression was higher in three treatment groups, and caspase3 activity increased in SM and SL groups, suggesting that short daylight can induce apoptosis. DRP1 protein expression showed no difference in four groups, while the FIS1 protein expression was significantly decreased in three treatment groups, this indicates that short daylight and mild low temperature can increase mitochondrial fission level. PINK1 protein expression was significantly increased in ML and SL groups, indicates that mild low temperature will lead to increased mitophagy level. Generally, short daylight induced degeneration of mitochondria in the testis of hamsters mainly by increasing apoptosis, while under mild low temperature, balanced regulation of mitophagy and mitochondrial fission appear to contribute to the protection of mitochondria.

Shedding light on the pedestrian safety crisis: An analysis across the injury severity spectrum by lighting condition

Objective Pedestrian fatalities in the United States increased 51% from 2009 to 2019. During that time, pedestrian fatalities occurring at night increased by 63.7%, compared to a 17.6% increase for pedestrian fatalities occurring during daylight conditions. Have there also been increases in serious, minor, and possible pedestrian injuries (i.e., have all pedestrian collisions been occurring more frequently)? Have pedestrian collisions been getting more severe (i.e., are there now higher proportions of more severe injuries)? Have trends differed between night and day? What role does street lighting play in the nighttime trends? Methods We analyzed pedestrian fatalities, serious injuries, minor injuries, and possible injuries that occurred in California, North Carolina, and Texas from 2010 to 2019 using linear regressions to explore the strength and statistical significance of trends. We then parsed these trends by lighting condition, exploring outcomes during the day and night and with and without street lighting. Results Findings suggest that increases in daytime minor (7.9%) and possible (7.5%) injuries closely mirrored increases in population (9.8%). Increases in daytime fatal/serious injuries were significantly higher (43.1% and 35.1%, respectively), suggesting worsening severities during the day. Increases in nighttime minor/possible injuries (31.9% and 27.6%, respectively) were significantly larger than those during the day, suggesting that pedestrian collisions are occurring more frequently at night. Substantial increases in nighttime fatal/serious injuries (78.0% and 74.7%, respectively) likely reflect a combination of worsening severity (seen throughout the day) and increasing frequency (seen particularly at night). A pedestrian injured in the dark was found to be 5.0 times more likely to be killed than a pedestrian injured during the day. While a lack of street lighting does not seem to be the cause of the disproportionate increase in pedestrian injuries at night, pedestrians struck without a street light were 2.4 times more likely to be killed than those struck in the presence of a street light. Conclusions As we find ourselves in the midst of a pedestrian safety crisis, understanding that severities have increased throughout the entire day and frequencies have increased particularly at night helps illuminate a path forward.

Algorithmic insights of camera-based respiratory motion extraction

Objective. Measuring the respiratory signal from a video based on body motion has been proposed and recently matured in products for contactless health monitoring. The core algorithm for this application is the measurement of tiny chest/abdominal motions induced by respiration (i.e. capturing sub-pixel displacement caused by subtle motion between subsequent video frames), and the fundamental challenge is motion sensitivity. Though prior art reported on the validation with real human subjects, there is no thorough or rigorous benchmark to quantify the sensitivities and boundary conditions of motion-based core respiratory algorithms. Approach. A set-up was designed with a fully-controllable physical phantom to investigate the essence of core algorithms, together with a mathematical model incorporating two motion estimation strategies and three spatial representations, leading to six algorithmic combinations for respiratory signal extraction. Their promises and limitations are discussed and clarified through the phantom benchmark. Main results. With the variation of phantom motion intensity between 0.5 mm and 8 mm, the recommended approach obtains an average precision, recall, coverage and MAE of 88.1%, 91.8%, 95.5% and 2.1 bpm in the day-light condition, and 81.7%, 90.0%, 93.9% and 4.4 bpm in the night condition. Significance. The insights gained in this paper are intended to improve the understanding and applications of camera-based respiration measurement in health monitoring. The limitations of this study stem from the used physical phantom that does not consider human factors like body shape, sleeping posture, respiratory diseases, etc., and the investigated scenario is focused on sleep monitoring, not including scenarios with a sitting or standing patient like in clinical ward and triage.