High Line Density Research Articles

Globin: A spectropolarimetric inversion code for the coupled inference of atomic line parameters

Context. The reliability of physical parameters describing the solar atmosphere inferred from observed spectral line profiles depends on the accuracy of the involved atomic parameters. For many transitions, atomic data, such as the oscillator strength (log(gf)) and the central wavelength of the line, are poorly constrained or even unknown. Aims. We present and test a new inversion method that infers atomic line parameters and the height stratification of the atmospheric parameters from spatially resolved spectropolarimetric observations of the Sun. This method is implemented in the new inversion code globin. Methods. The new method employs a global minimization algorithm enabling the coupling of inversion parameters common to all pixels, such as the atomic parameters of the observed spectral lines. At the same time, it permits the optimum atmospheric parameters to be retrieved individually for each spatial pixel. The uniqueness of this method lies in its ability to retrieve reliable atomic parameters even for heavily blended spectral lines. We tested the method by applying it to a set of 18 blended spectral lines between 4015 Å and 4017 Å, synthesized from a 3D magnetohydrodynamic simulation containing a sunspot and the quiet Sun region around it. The results were then compared with a previously used inversion method where atomic parameters were determined for every pixel independently (pixel-by-pixel method). For the same spectral region, we also inferred the atomic parameters from the synthesized spatially averaged disc-centre spectrum of the quiet-sun. Results. The new method was able to retrieve the log(gf) values of all lines to an accuracy of 0.004 dex, while the pixel-by-pixel method retrieved the same parameter to an accuracy of only 0.025 dex. The largest differences between the two methods are evident for the heavily blended lines, with the former method performing better than the latter. In addition, the new method is also able to infer reliable atmospheric parameters in all the inverted pixels by successfully disentangling the degeneracies between the atomic and atmospheric parameters. Conclusions. The new method is well suited for the reliable determination of both atomic and atmospheric parameters and works well on all spectral lines, including those that are weak and/or severely blended. This is of high relevance, especially for the analysis of observations of spectral regions with a very high density of spectral lines. An example includes the future near-ultraviolet spectropolarimetric observations of the SUNRISE III stratospheric balloon mission.

Overview of the contributions from all lanthanide elements to kilonova opacity in the temperature range from 25 000 to 40 000 K

Context. It is now well established that the neutron star (NS) merger is at the origin of the production of trans-iron heavy elements in the universe. These elements are therefore present in large quantities in the ejected matter, whose electromagnetic radiation, called kilonova, is characterized by a significant opacity due to the high density of spectral lines belonging to many heavy ions. Among these, the lanthanide ions play an essential role since, with their open 4f subshell, they have a considerable number of transitions that can absorb emitted light. The knowledge of the atomic structure and the radiative parameters of these ions as well as the determination of the corresponding opacities is therefore of paramount importance for the spectral analysis of kilonovae. Aims. The main goal of the present work is to determine the relative contributions of the different lanthanide elements to the opacity of the emission spectrum of a kilonova in its early phase, that is, a few hours after the NS merger, where the conditions are such that the temperature is between 25 000 and 40 000 K. At these temperatures, the lanthanide ions whose charge states are between V and VII are predominant. Methods. We used the pseudo-relativistic Hartree–Fock (HFR) method extensively to calculate the relevant atomic data (energy levels, wavelengths, and oscillator strengths) in La-Lu V-VII ions. The corresponding monochromatic opacities were estimated from the expansion formalism. Results. We calculated the spectroscopic parameters for a total of more than 800 million radiative transitions in all the ions considered. These data were used to estimate the expansion opacities and Planck mean opacities for all the lanthanide elements at early-phase kilonova conditions between 25 000 and 40 000 K, making it possible to deduce the respective contributions of each element as a function of temperature. Atomic calculations were also carried out with the fully relativistic Multiconfiguration Dirac-Hartree-Fock (MCDHF) method in the specific case of the Yb V ion, as the available experimental data had not yet been compared with the theoretical calculations in our previous studies on lanthanide ions.

Phase demodulation method of high line density grating interferometric signal based on wavelet transform

The increasing line density of the reference grating and the accelerating miniaturization of ultra-precision displacement measurement technology necessitate more stable interferometric signal processing methods for high line density gratings, particularly in low signal-to-noise ratio scenarios. This paper presents a phase demodulation method for dynamic interferometric signals for high line density gratings. The Morlet wavelet transform is utilized to obtain the instantaneous frequency of the interferometric signal, integration of which yields the relative displacement, while adding adjacent relative displacements without gaps provides the absolute displacement during dynamic motion of the grating. In simulations with a signal-to-noise ratio ranging from 40 to 70 dB, the proposed method demonstrates greater robustness compared to the traditional method. By establishing a platform for repeated experiments and comparing it with traditional methods, it was found that the maximum deviation between calculation results obtained using this method and traditional methods is 0.8 nm, further confirming its potential application.

Structure, variability, and origin of the low-latitude nightglow continuum between 300 and 1800 nm: evidence for HO2 emission in the near-infrared

Abstract. The Earth's mesopause region between about 75 and 105 km is characterised by chemiluminescent emission from various lines of different molecules and atoms. This emission was and is important for the study of the chemistry and dynamics in this altitude region at nighttime. However, our understanding is still very limited with respect to molecular emissions with low intensities and high line densities that are challenging to resolve. Based on 10 years of data from the astronomical X-shooter echelle spectrograph at Cerro Paranal in Chile, we have characterised in detail this nightglow (pseudo-)continuum in the wavelength range from 300 to 1800 nm. We studied the spectral features, derived continuum components with similar variability, calculated climatologies, studied the response to solar activity, and even estimated the effective emission heights. The results indicate that the nightglow continuum at Cerro Paranal essentially consists of only two components, which exhibit very different properties. The main structures of these components peak at 595 and 1510 nm. While the former was previously identified as the main peak of the FeO “orange arc” bands, the latter is a new discovery. Laboratory data and theory indicate that this feature and other structures between about 800 and at least 1800 nm are caused by emission from the low-lying A′′ and A′ states of HO2. In order to test this assumption, we performed runs with the Whole Atmosphere Community Climate Model (WACCM) with modified chemistry and found that the total intensity, layer profile, and variability indeed support this interpretation, where the excited HO2 radicals are mostly produced from the termolecular recombination of H and O2. The WACCM results for the continuum component that dominates at visual wavelengths show good agreement for FeO from the reaction of Fe and O3. However, the simulated total emission appears to be too low, which would require additional mechanisms where the variability is dominated by O3. A possible (but nevertheless insufficient) process could be the production of excited OFeOH by the reaction of FeOH and O3.

Reactive oxygen species may be involved in the distinctive biological effects of different doses of 12C6+ ion beams on Arabidopsis.

Heavy ion beam is a novel approach for crop mutagenesis with the advantage of high energy transfer line density and low repair effect after injury, however, little investigation on the biological effect on plant was performed. 50 Gy irradiation significantly stimulated the growth of Arabidopsis seedlings, as indicated by an increase in root and biomass, while 200 Gy irradiation significantly inhibited the growth of seedlings, causing a visible decrease in plant growth. The Arabidopsis seeds were irradiated by 12C6+. Monte Carlo simulations were used to calculate the damage to seeds and particle trajectories by ion implantation. The seed epidermis received SEM detection and changes in its organic composition were detected using FTIR. Evidence of ROS and antioxidant systems were analyzed. RNA-seq and qPCR were used to detect changes in seedling transcript levels. Monte Carlo simulations revealed that high-dose irradiation causes various damage. Evidence of ROS and antioxidant systems implies that the emergence of phenotypes in plant cells may be associated with oxidative stress. Transcriptomic analysis of the seedlings demonstrated that 170 DEGs were present in the 50 Gy and 200 Gy groups and GO enrichment indicated that they were mainly associated with stress resistance and cell wall homeostasis. Further GO enrichment of DEGs unique to 50 Gy and 200 Gy revealed 58 50Gy-exclusive DEGs were enriched in response to oxidative stress and jasmonic acid entries, while 435 200 Gy-exclusive DEGs were enriched in relation to oxidative stress, organic cyclic compounds, and salicylic acid. This investigation advances our insight into the biological effects of heavy ion irradiation and the underlying mechanisms.

Giant Rashba-splitting of one-dimensional metallic states in Bi dimer lines on InAs(100).

Bismuth produces different types of ordered superstructures on the InAs(100) surface, depending on the growth procedure and coverage. The (2 × 1) phase forms at completion of one Bi monolayer and consists of a uniformly oriented array of parallel lines of Bi dimers. Scanning tunneling and core level spectroscopies demonstrate its metallic character, in contrast with the semiconducting properties expected on the basis of the electron counting principle. The weak electronic coupling among neighboring lines gives rise to quasi one-dimensional Bi-derived bands with open contours at the Fermi level. Spin- and angle-resolved photoelectron spectroscopy reveals a giant Rashba splitting of these bands, in good agreement with ab initio electronic structure calculations. The very high density of the dimer lines, the metallic and quasi one-dimensional band dispersion and the Rashba-like spin texture make the Bi/InAs(100)-(2 × 1) phase an intriguing system, where novel transport regimes can be studied.

High efficiency multilayer coated laminar gratings with high line density for tender X-ray region

Driven by the demand of high efficiency and high resolution monochromators and spectrometers in the tender X-ray range, high line density multilayer coated laminar gratings (MLLG) were designed, manufactured, and analyzed. Theoretical simulations displayed that a 5000 l/mm MLLG could realize high resolution at 3 keV and 40 times higher diffraction efficiency than the single-layer coated grating. For the first demonstration of the high line density MLLGs, two 3000 l/mm laminar gratings were fabricated and coated by Cr/C multilayers with different periodic thicknesses to achieve high efficiency (HE) and high resolution (HR) performance. For MLLG-HE, a maximum efficiency of 54.5% was achieved at 4.4 keV. For MLLG-HR, relatively high efficiency of 23.1%–38.6% were demonstrated with much stronger asymmetric diffraction in 2–4 keV, which can significantly increase the energy resolution of the system.

Microstructure sensitivity of the low cycle fatigue crack initiation mechanisms for the Al0.3CoCrFeNi high entropy alloy: in-situ SEM study and crystal plasticity simulation

In this study, in-situ fatigue tests under scanning electron microscopy (SEM) were performed to reveal the relationship between grain slip deformation and fatigue crack initiation of Al0.3CoCrFeNi high entropy alloy (HEA). It was found that the fine grains (FG) exhibited a higher fatigue crack initiation life than that of the coarse grains (CG), which is related to the inhibition effects of twins and grain boundaries on fatigue crack initiation. The initiation of fatigue cracks in both the CG and FG specimens occurred in the area of high density of slip lines. The fatigue cracks were observed to deviate from the single slip line, which is related to the activation of multiple slip systems inside the grain, leading to the alternation of fatigue crack propagation path. In addition, the intersection of different slip planes can be another preferential crack initiation site if two or more slip planes are activated inside one grain. By combining EBSD analysis and crystal plasticity finite element modeling (CPFEM), the influence of microstructures, such as grain orientation and grain boundaries, on the fatigue crack initiation mechanism was further analyzed. The CPFEM results confirmed that the CG specimen resulted in a higher cumulative shear strain (CSS) than that of the FG specimen under the same stress level, which led to higher fatigue damage.

The CARMENES search for exoplanets around M dwarfs

Context. Radial velocities (RVs) measured from high-resolution stellar spectra are routinely used to detect and characterise orbiting exoplanet companions. The different lines present in stellar spectra are created by several species, which are non-uniformly affected by stellar variability features such as spots or faculae. Stellar variability distorts the shape of the spectral absorption lines from which precise RVs are measured, posing one of the main problems in the study of exoplanets. Aims. In this work we aim to study how the spectral lines present in M dwarfs are independently impacted by stellar activity. Methods. We used CARMENES optical spectra of six active early- and mid-type M dwarfs to compute line-by-line RVs and study their correlation with several well-studied proxies of stellar activity. Results. We are able to classify spectral lines based on their sensitivity to activity in five M dwarfs displaying high levels of stellar activity. We further used this line classification to compute RVs with activity-sensitive lines and less sensitive lines, enhancing or mitigating stellar activity effects in the RV time series. For specific sets of the least activity-sensitive lines, the RV scatter decreases by ~2 to 5 times the initial one, depending on the star. Finally, we compare these lines in the different stars analysed, finding the sensitivity to activity to vary from star to star. Conclusions. Despite the high density of lines and blends present in M dwarf stellar spectra, we find that a line-by-line approach is able to deliver precise RVs. Line-by-line RVs are also sensitive to stellar activity effects, and they allow for an accurate selection of activity-insensitive lines to mitigate activity effects in RV. However, we find stellar activity effects to vary in the same insensitive lines from star to star.

Upscaling cultivation of Saccharina latissima on net or line systems; comparing biomass yields and nutrient extraction potentials

Production of sugar kelp, Saccharina latissima, has the potential of extracting nutrients and carbon from the seawater and returning it to land as a bioresource. The production thereby acts as an emission capture and utilization instrument contributing to mitigation of eutrophication and climate change. To achieve higher biomass yields improving the effects on climate and environment, and the economic feasibility of the production, cultivation techniques need to be optimized. In Denmark so far, S. latissima production yields have been lower than yields documented from Norway and the Faroe Islands. Use of alternative cultivation infrastructure designs with a higher line density per area, and better understanding the effects of annual and seasonal variations in abiotic parameters on growth, could lead the way towards a future higher yield of the S. latissima production. In this study, S. latissima was cultivated in a Danish commercial scale cultivation site for two consecutive seasons comparing the yields of different cultivation techniques: cultivation on nets and a multi-layer single line system, while also testing the possibility of coppicing the blades instead of applying a full harvest. Biomass yields of 5.0 - 6.8 kg FW m-1 cultivation line year-1, and 10.9 – 30.4 kg FW m-2 net structure were achieved. Biomass production, nutrient and carbon extraction potentials up to 91.3 t FW, 110 kg N, 13.1 kg P and 5.1 t C ha-1 were obtained using net cultivation systems and a 1.5 years growth period. Depth of cultivation had a significant effect on yield, but no effect on dry matter, C, N or P contents of S. latissima in a multi-layered line system. Biomass yields from the same system and site varied with a factor of four between years. The use of coppicing enabled multiple harvests of S. latissima, providing however biomass of reduced quality in the second year. This study demonstrates that the production yield of S. latissima can be increased by optimizing cultivation infrastructure, and indicates that net systems, or other cultivation systems with a high line density in the upper water column, can be a means to increase the areal yield of S. latissima.

Absolute frequencies of H13C14N hydrogen cyanide transitions in the 1.5-µm region with the saturated spectroscopy and a sub-kHz scanning laser.

The wide span and high density of lines in its rovibrational spectrum render hydrogen cyanide a useful spectroscopic media for referencing absolute frequencies of lasers in optical communication and dimensional metrology. We determined, for the first time to the best of our knowledge, the molecular transitions' center frequencies of the H13C14N isotope in the range from 1526 nm to 1566 nm with 1.3×10-10 fractional uncertainty. We investigated the molecular transitions with a highly coherent and widely tunable scanning laser that was precisely referenced to a hydrogen maser through an optical frequency comb. We demonstrated an approach to stabilize the operational conditions needed to maintain the constantly low pressure of the hydrogen cyanide to carry out the saturated spectroscopy with the third-harmonic synchronous demodulation. We demonstrated approximately a forty-fold improvement in the line centers' resolution compared to the previous result.

High-efficiency, polarization-insensitive 1400-lines/mm retroreflective metagrating with cascaded nano-optical modes

A retroreflective grating with a high line density is one of the most desirable optical elements, as it is capable of channeling the reflected light toward the source with high angular resolution. Metagratings can steer the incident light into the desired diffraction order with ultrahigh deflection angle and unitary efficiency. However, in practice, the diffraction efficiency of a metagrating with a small period is very sensitive to the unit cells, thus leading to significant challenges in the fabrication process. In this Letter, a kind of high-efficiency, polarization-insensitive retroreflective metagrating with cascaded nano-optical modes on high-reflection films is proposed. It is found that the conception may increase the fabrication tolerance by a factor of more than two. A 1400-lines/mm metagrating is experimentally realized for the first time, to the best of our knowledge, which shows an excellent broadband diffraction spectrum with 96% efficiency over 50 nm in TE and TM polarization. This proposed novel metagrating will benefit miniature optical systems.

Enabling safe passage: predicting river crossing hotspots for a threatened boreal ungulate susceptible to drowning

Abstract Many mammals cross large rivers to access seasonal habitats, yet river crossing behavior is poorly acknowledged or understood. Crossing large rivers is inherently risky, with vessel traffic and flooding events increasing the risk of drowning. We investigated river crossing behavior by threatened bison (Bison bison) in the boreal forest, using data from 11 GPS-collared animals to identify when and where they cross a major river. We used kernel densities of GPS locations to identify crossing hotspots, and developed resource selection function (RSF) models that used habitat characteristics to explain crossing behavior based on a priori hypotheses. We then predicted high-probability crossing areas along a 400-km stretch of river using the best-supported RSF model. Bison regularly crossed the river (x¯ = 8.6 crossings/100 days), particularly during summer months. Model selection results suggested that bison may have chosen river crossing areas that maximized access to forage. Bison preferred to cross the river near islands and areas with high seismic line densities, both of which were likely preferred summer foraging habitats. In addition, islands may have been used as temporary stopovers while crossing the river, or for relief from biting insects. Bison crossed the river where the channel was relatively narrow (x¯ = 400 ± 213 m [SD]) and chose days when river discharge was low, likely to reduce the risk of drowning, exhaustion, or hypothermia. While based on a small sample of collared bison, predictions about high-probability crossing areas may be used to inform mitigation measures aimed at reducing bison drowning caused by vessel traffic, which is expected to increase as resource development expands in the region. Our approach may be informative for identifying river crossing hotspots for other mammals that cross major rivers.

Design method of worn rail grinding profile based on Frechet distance method

Due to the large volume and high running density of railway freight lines, rail deterioration occur frequently. Thus, it is necessary to grind the rail in time to improve the wheel-rail relationship. The profile data of the worn rail were measured at different measuring points in a section, and the Frechet distance method was adopted to analyze the data. The representative profile reflecting the overall condition of rail wear in this section is obtained. Combined with NURBS curve theory, a fitting algorithm in which the rail profile with certain discrete points was established. Taking the reduction of the amount of grinding material removed as the objective function, setting wheel-rail matching characteristics, and the reduction of rail wear as the constraint conditions, a calculation model for rail grinding profile was established. The dynamic characteristics of standard profile CN75 and g grinding profile OP75 were analyzed by the vehicle track dynamics model. The results showed that compared with the standard profile CN75, the amount of grinding material removed of the grinding profile OP75 is reduced by 44.7%, and the height reduction of the rail top is reduced by 0.39 mm. After [Formula: see text] km of running, the wear amounts of grinding profile OP75 is about 36.1%–36.5% less than that of standard profile CN75.In the small curve section, the derailment coefficient of grinding profile OP75 is reduced by 11.7% compared with that of standard profile CN75. The dynamic performance is improved. The grinding target profile has better dynamic characteristics and is beneficial to reduce wheel-rail wear.

Flight altitudes of a soaring bird suggest landfill sites as power line collision hotspots

Anthropogenic structures are increasingly encroaching wildlife habitats, creating conflicts between humans and animals. Scaling up renewable energy requires new infrastructures such as power lines, that cause high mortality among birds since they act as obstacles to flight and are used for perching and nesting, which can result in collisions or electrocutions. These interactions often endanger wildlife populations and may also result in high financial costs for companies. Flight behaviour plays a crucial role in collision risk, and the study of flight altitudes enables us to understand what drives birds to fly at collision risk altitudes. This allows the identification of high-risk areas, conditions and bird behaviours, and the implementation of mitigation measures by power line companies. In this study, we use boosted random tree modelling to identify drivers of white stork (Ciconia ciconia) flight altitudes and to investigate the factors that lead them to fly at collision risk altitudes. We found that the main drivers of flight altitude for this soaring bird species were time of day, distance to the nearest landfill site and cloud cover density. Bird age, habitat type and season were comparatively less important. Collision risk increases during crepuscular hours near landfill sites, also in days with high cloud cover density and during the breeding season. In recent years, hundreds to thousands of storks congregate daily at landfill sites to take advantage of the predictability and superabundance of anthropogenic food waste. Some of these sites have high density of power lines, becoming collision risk hotspots for storks and other landfill users. Despite being susceptible to collision, our results suggest that white storks can avoid power lines to a certain extent, by changing their flight altitude at ca. 80 m from these structures. This study shows that the implementation of mitigation measures for existing power lines should be prioritized in areas in the vicinity of landfill sites within white stork distribution ranges, and the projection of new lines should avoid those areas. These measures would benefit species vulnerable to mortality due to power line collision, and it would also reduce associated power outages and economic costs.

Study on High Precision Fabric Density Measuring Instrument and Measuring Method Based on Moire Fringe

With the continuous development of science and the continuous progress and reform of fabric knitting technology, all kinds of fabrics continue to appear. Linear density is one of the most important physical and geometric characteristics of knitted fabrics, which affects the physical and mechanical properties, feel and style of textiles, and is one of the important bases for fabric design and manufacturing process parameters.In this paper, a device and method is developed, which is not affected by the width and density of fabric lines, and can accurately measure the density of fabric. The invention puts forward a method of measuring fabric density from a new point of view. Using the phenomenon of moire fringes, the fabric density of the fabric to be measured is calculated by measuring the angle. The device has the advantages of simple structure, low production cost, and is not affected by the width and density of cloth lines. it can measure fabrics with high line density or wide lines, and has the advantages of high precision and convenient operation. and the gratings with different grating constants can be selected according to the characteristics of the fabric, which has a very wide range of application.

First-trimester fetal heart evaluation: time to move forward.

First-trimester fetal heart evaluation: time to move forward.

Thermal strain imaging in vivo using interpolated IQ-images

Thermal strain imaging (TSI) is a promising technique for ultrasonic thermometry, especially in the applications of thermal therapies. The accuracy of TSI is dependent on the sampling rate and line density of B-Scan images, and the prevalent IQ-demodulated ultrasound data outputted from low- and middle-end machines are therefore insufficient. Here, the feasibility of using interpolated IQ images for TSI (based on the “infinitesimal echo strain filter” model) is studied through in vivo experiments targeting the perirenal fat of pigs. It is demonstrated that, axial interpolations, especially those using the zero-padding algorithm, can recover the capabilities of the low-sampling-rate complex IQ images in TSI, and make their performances comparable to those of RF/IQ complex images with higher sample rate. Meanwhile, interpolations along the lateral direction can increase the line density of IQ images, reduce TSI errors, and reveal more details in the temperature maps. In the experiments, the variation in the thermometry coefficient (the k-value) is well below 3%. The findings here bring down the requirement of high sampling rate as well as high line density of US images in TSI, making it possible to be applied on common US machines.

RASSINE: Interactive tool for normalising stellar spectra

Aims. We provide an open-source code allowing an easy, intuitive, and robust normalisation of spectra. Methods. We developed RASSINE, a Python code for normalising merged 1D spectra through the concepts of convex hulls. The code uses six parameters that can be easily fine-tuned. The code also provides a complete user-friendly interactive interface, including graphical feedback, that helps the user to choose the parameters as easily as possible. To facilitate the normalisation even further, RASSINE can provide a first guess for the parameters that are derived directly from the merged 1D spectrum based on previously performed calibrations. Results. For HARPS spectra of the Sun that were obtained with the HELIOS solar telescope, a continuum accuracy of 0.20% on line depth can be reached after normalisation with RASSINE. This is three times better than with the commonly used method of polynomial fitting. For HARPS spectra of α Cen B, a continuum accuracy of 2.0% is reached. This rather poor accuracy is mainly due to molecular band absorption and the high density of spectral lines in the bluest part of the merged 1D spectrum. When wavelengths shorter than 4500 Å are excluded, the continuum accuracy improves by up to 1.2%. The line-depth precision on individual spectrum normalisation is estimated to be ∼0.15%, which can be reduced to the photon-noise limit (0.10%) when a time series of spectra is given as input for RASSINE. Conclusions. With a continuum accuracy higher than the polynomial fitting method and a line-depth precision compatible with photon noise, RASSINE is a tool that can find applications in numerous cases, for example stellar parameter determination, transmission spectroscopy of exoplanet atmospheres, or activity-sensitive line detection.

Towards more sustainable transport in Metro Manila: A case study of household vehicle ownership and energy consumption

Improvement of residential areas with low accessibility to crucial destinations (e.g., hospitals, schools, markets, and recreation centers) is expected to improve traffic flow and reduce energy consumption and CO2 emissions. This study intends to evaluate the multi-criteria accessibility measure of residential areas to key destinations in Metro Manila, using the gravity method and applying it to understand its impact on household vehicle ownership and energy consumption. The main findings suggest that improving residential area access to key services and facilities (i.e., hospitals, schools, markets, and recreation centers) not only enhances the equitable development of society but also discourages household vehicle dependency. Additionally, the highest multi-criteria accessibility is observed for areas with the presence of high rail line density, specifically in the most populated part of Metro Manila because of many educational institutions, medical centers and hospitals, and markets and shopping malls are located around the train stations and along the rail lines. Furthermore, households living in an area with high multi-criteria accessibility are less likely to acquire and use vehicles. A 1% improvement of accessibility reduced the energy consumption by 38.470 MJ/month-vehicle, CO2 emission by 2.851 kg/month-vehicle, and vehicle kilometers traveled by 12.043 km/month-vehicle. Based on the empirical findings, policy implications recommend building more key facilities in residential areas having the lowest accessibility. The lowest accessibility areas are also geospatially visualized to support policymakers and urban planners.