Full Spectral Analysis Research Articles

Machine Learning and New-Generation Spaceborne Hyperspectral Data Advance Crop Type Mapping

Hyperspectral sensors provide near-continuous spectral data that can facilitate advancements in agricultural crop classification and characterization, which are important for addressing global food and water security issues. We investigated two new-generation hyperspectral sensors, Germany’s Deutsches Zentrum für Luft‐ und Raumfahrt Earth Sensing Imaging Spectrometer (DESIS) and Italy’s PRecursore IperSpettrale della Missione Applicativa (PRISMA), within California???s Central Valley in August 2021 focusing on five irrigated agricultural crops (alfalfa, almonds, corn, grapes, and pistachios). With reference data from the U.S. Department of Agriculture Cropland Data Layer, we developed a spectral library of the crops and classified them using three machine learning algorithms (support vector machines [SVM], random forest [RF], and spectral angle mapper [SAM]) and two philosophies: 1. Full spectral analysis (FSA) and 2. Optimal hyperspectral narrowband (OHNB) analysis. For FSA, we used 59 DESIS four-bin product bands and 207 of 238 PRISMA bands. For OHNB analysis, 9 DESIS and 16 PRISMA nonredundant OHNBs for studying crops were selected. FSA achieved only 1% to 3% higher accuracies relative to OHNB analysis in most cases. SVM provided the best results, closely followed by RF. Using both DESIS and PRISMA image OHNBs in SVM for classification led to higher accuracy than using either image alone, with an overall accuracy of 99%, producer’s accuracies of 94% to 100%, and user???s accuracies of 95% to 100%.

ALMA Lensing Cluster Survey: Full Spectral Energy Distribution Analysis of z ∼ 0.5–6 Lensed Galaxies Detected with millimeter Observations

Sub/millimeter galaxies are a key population for the study of galaxy evolution because the majority of star formation at high redshifts occurred in galaxies deeply embedded in dust. To search for this population, we have performed an extensive survey with Atacama Large Millimeter/submillimeter Array (ALMA), called the ALMA Lensing Cluster Survey (ALCS). This survey covers 133 arcmin2 area and securely detects 180 sources at z ∼ 0.5–6 with a flux limit of ∼0.2 mJy at 1.2 mm. Here, we report the results of multiwavelength spectral energy distribution analysis of the whole ALCS sample, utilizing the observed-frame UV to millimeter photometry. We find that the majority of the ALCS sources lie on the star-forming main sequence, with a smaller fraction showing intense starburst activities. The ALCS sample contains high infrared-excess sources ( IRX=log(Ldust/LUV)>1 ), including two extremely dust-obscured galaxies (IRX > 5). We also confirm that the ALCS sample probes a broader range in lower dust mass than conventional submillimeter galaxy samples in the same redshift range. We identify six heavily obscured active galactic nucleus (AGN) candidates that are not detected in the archival Chandra data in addition to the three X-ray AGNs reported by Uematsu et al. (2023). The inferred AGN luminosity density shows a possible excess at z = 2–3 compared with that determined from X-ray surveys below 10 keV.

Assessment of the impact of vehicle emissions on the geoecological state of soils and vegetation in the cities of the Irkutsk agglomeration

The study examines the problem of the influence of vehicle emissions on the condition of soils and vegetation of roadside strips in the cities of the Irkutsk agglomeration. Sampling was carried out near intersections characterized by intense traffic flows. As a result of a mass (semi-quantitative) full spectral analysis of selected samples, the content of heavy metals in them was revealed to be higher than the maximum permissible and background concentrations. Calculations of the total pollution indicator were carried out, which made it possible to establish that the soils of roadside zones in urbanized areas of the agglomeration belong to the categories “dangerous” and “extremely dangerous”. Recommendations for improving the geoecological condition of soils and vegetation in urban areas are given.

Estimating stellar population and emission-line properties in S-PLUS galaxies

ABSTRACT We present tests of a new method to simultaneously estimate stellar population and emission-line (EL) properties of galaxies out of the Southern Photometric Local Universe Survey (S-PLUS) photometry. The technique uses the AlStar code, updated with an empirical prior that greatly improves its ability to estimate ELs using only the survey’s 12 bands. The tests compare the output of (noise-perturbed) synthetic photometry of the Sloan Digital Sky Survey (SDSS) galaxies to properties derived from previous full spectral fitting and detailed EL analysis. For realistic signal-to-noise ratios, stellar population properties are recovered to better than 0.2 dex in masses, mean ages, metallicities, and ±0.2 mag for the extinction. More importantly, ELs are recovered remarkably well for a photometric survey. We obtain input − output dispersions of 0.05–0.2 dex for the equivalent widths of [O ii], [O iii], Hβ, Hα, [N ii], and [S ii], and even better for lines stronger than ∼5 Å. These excellent results are achieved by combining two empirical facts into a prior that restricts the EL space available for the fits. (1) Because, for the redshifts explored here, Hα and [N ii] fall in a single narrow band (J0660), their combined equivalent width is always well recovered, even when [N ii]/Hα is not. (2) We know from SDSS that $W_{\mathrm{H}\alpha +[\mathrm{N}\,\small {\rm II}] }$ correlates with [N ii]/Hα, which can be used to tell if a galaxy belongs to the left or right wings in the classical Baldwin–Phillips–Telervich (BPT) diagnostic diagram. Example applications to integrated light and spatially resolved data are also presented, including a comparison with independent results obtained with the Multi-Unit Spectroscopic Explorer (MUSE)-based integral field spectroscopy.

A neutron star candidate in the long-period binary 56 UMa

Context. 56 UMa is a wide binary system that contains a chemically peculiar red giant and a faint companion. Due to its surface chemical abundances, the red giant was classified as a barium (Ba) star. This implies that the companion has to be a white dwarf, since Ba stars form when mass is transferred to them from an s-process rich Asymptotic Giant Branch (AGB) star. However, in the case of 56 UMa, the companion might be too massive to be the progeny of an AGB star that efficiently produced s-process elements such as barium. Aims. In this Letter, we revisit the orbital parameters of the system and perform a full spectral analysis with the goal of investigating the Ba-star classification of the giant and unravelling the nature of its faint companion. Methods. We combined radial-velocity and astrometric data to refine the orbital parameters of the system, including the orbital inclination and the companion mass. Then, we re-determined the stellar parameters of the giant and its chemical abundances using high-resolution HERMES spectra. Finally, we investigated the morphology of the interstellar gas in the vicinity of the system. Results. The faint component in 56 UMa has a mass of 1.31 ± 0.12 M⊙, which, together with the mixed s + r abundance profile of the red giant, confirms that the giant is not a standard barium star. Additionally, the clear identification of a cavity surrounding 56 UMa could indicate that a supernova explosion occurred about 105 years ago in the system, suggesting that the faint companion might be a neutron star. However, finding an evolutionary scenario that explains all the observables is not trivial, so we discuss different possible configurations of the system and their respective merits.

Gamma ray full spectral analysis method optimization of an ill-conditioned problem

Gamma ray full spectral analysis method optimization of an ill-conditioned problem

Near-infrared hyperspectral imaging for evaluation of aflatoxin contamination in corn kernels

Aflatoxins are among the most carcinogenic mycotoxins and are considered as the most problematic mycotoxins in U.S. agriculture. The innovative technologies that can offer high-throughput detection, advantages of rapidness and non-destructiveness are urgently needed. One such technology using the near-infrared hyperspectral imaging between 900 and 2500 nm was employed to distinguish aflatoxin contamination in corn kernels. Nine hundred kernels were used with 3 treatments, namely, each 300 kernels inoculated with the aflatoxigenic AF13 fungus, non-aflatoxigenic AF36 fungus, and sterile distilled water. One hundred kernels from each treatment group were subjected to incubation for 3, 5 and 8 days, dried and wiped to remove exterior fungus, and imaged. The reference aflatoxin concentration in each kernel was determined by the VICAM AflaTest method. The full spectral partial least-squares discriminant analysis (PLS-DA) results show that the models established upon the standard normal variate-preprocessed germ-side absorbance generally performed better. The models with different training sample size ratios in terms of aflatoxin-negative: -positive class, indicate that the 2:1 ratio achieved more balanced prediction performance. With the 20-ppb and 100-ppb thresholds, the type II- competitive adaptive reweighted sampling (CARS)-PLSDA models established upon the 17 and 21 commonly selected variables, under the conditions of “frequency ≥ 70” and “frequency ≥ 60” respectively in 100 random runs, achieved comparable prediction capability to the full spectral and type I-CARS-PLSDA models. The mean prediction accuracies of the aflatoxin-negative, -positive class and overall accuracy of the type II-CARS-PLSDA models, were 90.4%, 81.1% and 89.8%, and 89.7%, 82.8% and 89.3% using the 20-ppb and 100-ppb thresholds. • Corn kernels inoculated with aflatoxigenic and non-aflatoxigenic fungi included. • Effect of corn kernel side on discrimination results was investigated. • Effect of training sample size ratio of aflatoxin-negative: -positive was addressed. • Feature spectral variables determined with selection frequency taken into account. • Simplified discriminant models were established with 20- and 100-ppb thresholds.

The Full Informational Spectral Analysis for Auditory Steady-State Responses in Human Brain Using the Combination of Canonical Correlation Analysis and Holo-Hilbert Spectral Analysis.

Auditory steady-state response (ASSR) is a translational biomarker for several neurological and psychiatric disorders, such as hearing loss, schizophrenia, bipolar disorder, autism, etc. The ASSR is sinusoidal electroencephalography (EEG)/magnetoencephalography (MEG) responses induced by periodically presented auditory stimuli. Traditional frequency analysis assumes ASSR is a stationary response, which can be analyzed using linear analysis approaches, such as Fourier analysis or Wavelet. However, recent studies have reported that the human steady-state responses are dynamic and can be modulated by the subject’s attention, wakefulness state, mental load, and mental fatigue. The amplitude modulations on the measured oscillatory responses can result in the spectral broadening or frequency splitting on the Fourier spectrum, owing to the trigonometric product-to-sum formula. Accordingly, in this study, we analyzed the human ASSR by the combination of canonical correlation analysis (CCA) and Holo-Hilbert spectral analysis (HHSA). The CCA was used to extract ASSR-related signal features, and the HHSA was used to decompose the extracted ASSR responses into amplitude modulation (AM) components and frequency modulation (FM) components, in which the FM frequency represents the fast-changing intra-mode frequency and the AM frequency represents the slow-changing inter-mode frequency. In this paper, we aimed to study the AM and FM spectra of ASSR responses in a 37 Hz steady-state auditory stimulation. Twenty-five healthy subjects were recruited for this study, and each subject was requested to participate in two auditory stimulation sessions, including one right-ear and one left-ear monaural steady-state auditory stimulation. With the HHSA, both the 37 Hz (fundamental frequency) and the 74 Hz (first harmonic frequency) auditory responses were successfully extracted. Examining the AM spectra, the 37 Hz and the 74 Hz auditory responses were modulated by distinct AM spectra, each with at least three composite frequencies. In contrast to the results of traditional Fourier spectra, frequency splitting was seen at 37 Hz, and a spectral peak was obscured at 74 Hz in Fourier spectra. The proposed method effectively corrects the frequency splitting problem resulting from time-varying amplitude changes. Our results have validated the HHSA as a useful tool for steady-state response (SSR) studies so that the misleading or wrong interpretation caused by amplitude modulation in the traditional Fourier spectrum can be avoided.

Field-scale spatial correlation between soil and Vis-NIR spectra in the Cerrado biome of Central Brazil

Visible and near-infrared (Vis-NIR) spectroscopy is a tool to determine soil spatial variability and has been used to map soils and their properties. Considering that physical, chemical, mineralogical, and morphological soil properties can affect the intensity and the depth of the spectral reflectance band in the Vis-NIR region, the objectives of this work were to: (i) evaluate the potential of the reflectance inflection difference (RID) to discriminate soils; and (ii) verify potential spatial correlations of the RID with soil properties, compared with the full spectra, in order to build thematic maps at a field scale. In a farm of 375 ha, 78 soil samples from the 0.87–0.92-m depth were collected in a regular grid of 200 m, with a focus on the soil diagnostic horizon (Bw horizon). The sampled soils were a Latossolo Vermelho-Amarelo ácrico (Haplic Ferralsol) and a Latossolo Vermelho distrófico (Rhodic Ferralsol). Twenty-two physical, chemical, mineralogical, and morphological soil properties were determined, and the Vis-NIR spectra between 400 and 2500 nm were measured. Considering the presence of an inflection band and its relationship with soil properties, the spectral bands used to calculate the RID were between (base 1/base 2): 400–510, 730–930, 1290–1450, 1800–1950, 2000–2218, and 2218–2290 nm. The RID failed to map the spatial variability of soil properties, with a Kappa index of 39%; therefore, it is not a good parameter for building thematic maps of soil parameters. In addition, the complete spectrum (mainly in 400–510, 730–930, 1290–1450, 1800–1950, 2000–2218, and 2218–2290 nm) was better spatially correlated with soil properties than the decomposition of the spectrum by the RID. Soil classification and level of discretization as affected by spectral variability were also discussed here. Three soil groups were discriminated mainly by the Ki and Kr indexes and clay content. Moreover, the variability of the spectra was conditioned by the spatial variability of the mentioned variables. The clay content for soils with a discrepant particle size (group 1 compared with groups 2 and 3) and the Ki and Kr indexes for soils with a homogeneous particle size (between groups 2 and 3), associated with the full Vis-NIR spectral analysis, allowed building thematic maps with a good precision, without the need of mathematical models; this was possible by the modification of the reflectance intensity and the size of the concavity of the spectral band.

Effective properties of semitransparent radiative cooling materials with spectrally variable properties

• Radiative cooling with semitransparent radiative coating and participating substrate. • Iterative method to calculate effective radiative properties from spectrally variable parameters. • Overall estimation error of less than 0.2%. • Beneficial for applications requiring lumped solar and thermal radiation related parameters. Radiative cooling is a promising solid-state, non-vapor-compression technology for passive refrigeration and air conditioning. Although this phenomenon occurs naturally, achieving a significant amount of cooling to make it a technically and economically viable technology requires highly engineered, spectrally selective radiative surfaces. These characteristics make radiative cooling difficult to estimate, particularly when it is integrated with other systems such as photovoltaic panels or building envelopes. The complexity further increases when the substrate also participates in the radiative cooling (along with the radiative coating). Energy estimation is becoming increasingly critical because of the recent focus on the semitransparent radiative coatings that transmit a variety of colors to enhance the aesthetic appeal of the system. Here, we propose an iterative method to calculate the effective radiative properties, which provides the same net radiative cooling that would be observed using the spectral properties at both the coating and substrate surfaces. Compared to traditional methods that rely on either computationally expensive full spectral analysis or methods for averaging each radiative surface parameter locally, our proposed method focuses on calculating effective properties that provide the same the net cooling effect as a full spectral analysis by accounting the emissivity, absorptivity, and transmissivity collectively, thereby providing an overall estimation error of less than 0.2%. We believe that this study will be beneficial to the engineering communities that employ complex simulation codes and require lumped solar and thermal radiation related parameters.

Quaternion Fourier Transform spectral analysis of electrical currents for bearing faults detection and diagnosis

This paper suggests a new method for detecting and diagnosing bearing faults in three-phase asynchronous devices using the periodogram estimation of the Power Spectral Density of the three-phase electrical current space vector. Rather than a single single-phase spectral analysis or a space vector component spectral analysis using the classic Fourier Transform, The Quaternion Fourier Transform was used to do a full spectral analysis of the three-phase currents scheme. Spectral indicators are given from the Quaternion Power Spectral Density and their use suggested for accurate detection and diagnosis of bearing faults via the quaternion's formalism. To validate this approach, the proposed indicators were compared to fault indicators derived from a single-phase or inferred from the real and imaginary parts of the currents space vector. The results reveal that two of the new metrics outperform the classic ones derived from either single-phase spectral analysis or the three-phase space vector components spectral analysis (classification rates of 94.2 percent and 93.8 percent, respectively). These findings support the preference for three-phase approaches over single-phase approaches, as well as the ability to extend classical research methods developed for single-phase systems to three-phase systems using the Quaternion Fourier transform.

Synthesis and Characterization of Novel Functionally Substituted Planar Pyrimidothienoisoquinolines and Nonplanar (3aR, 4S, 9aS)-pyrazolo[3,4-g]isoquinolines.

7-Acetyl-8-aryl-4-cyano-1,6-dimethyl-6-hydroxy-5,6,7,8-tetrahydroisoquinolin-3(2H)-thiones 2a,b are prepared and dehydrated to give 7-acetyl-8-aryl-4-cyano-1,6-dimethyl-6-hydroxy-7,8-dihydrodroisoquinolin-3(2H)-thiones 6a,b via a novel method by heating with acetyl chloride in acetic acid. The reaction of both compounds 2a,b and 6a,b with N-aryl-2-chloroacetamides 7a–c under two different conditions gave the same corresponding products, 7-acetyl-8-aryl-3-(N-aryl)carbamoylmethylsulfanyl-4-cyano-1,6-dimethyl-7,8-dihydroisoquinolines 8a–e, in high yields. On treatment of compounds 8a,b,e in methanol with a slightly excess molar amount of sodium methoxide, they underwent intramolecular Thorpe–Ziegler cyclization followed by spontaneous aromatization, providing the planar 7-acetyl-1-amino-6-aryl-2-(N-aryl)carbamoyl-5,8-dimethyl-8,9-dihydrothieno[2,3-c] isoquinolines 9a,b,e in good yield. Cyclocondensation reactions of 6a,b with phenyl hydrazine, thiosemicarbazide, or hydrazine hydrate led to the formation of nonplanar (3aR, 4S, 9aS)-pyrazolo[3,4-g]isoquinolines 11a, 11b, and 13, respectively. The reaction of compound 13 with 2-chloromethylquinazolin-4(3H)-one in the presence of anhydrous sodium acetate gave the expected thienopyrazoloisoquinolone 14. Heating the latter compound (14) with triethyl orthoformate in glacial acetic acid afforded the fused heptacyclic compound 15. All of the synthesized compounds were characterized based on their full spectral analyses such as IR, 1H nuclear magnetic resonance (NMR), and mass spectrometry (MS). Moreover, the crystal structure of compound 6a was elucidated by X-ray diffraction analysis.

A full spectral analysis method for the gamma spectrum: weighted library least squares

An algebraic weighted library least squares method for gamma spectrum analysis is proven to make the analytical results more stable.

Spatiotemporal analysis of elastic and inelastic deformations in roof-rocks from seismological observations

The spatiotemporal analysis of seismic zones characterised by the scattering and accumulation of strain energy in the roof-rocks of the excavated longwall panel where inelastic or elastic deformations occurred during hard coal seam mining is discussed. The studied longwall panel was designed to utilize the effect of partial stress relaxation caused by the earlier extraction of the coal seams located above. A full seismic moment tensor and spectral source parameter analyses were used to obtain information about the degree of inelastic and elastic coseismic deformations. This study also showed that these deformation changes correspond to variation in the Benioff strain release characteristics. Next, analyses of deformation zones were compared with the relationship between radiated energy and the excavated volume of rocks per month. The concept of balanced seismic energy release assumed the exponential increase of released seismic energy with the increase in the volume of excavated rock. Discrepancies between the observed and predicted radiated energies indicated that strain energy in selected zones in the rock mass was either scattered if the prediction was overestimated, or accumulated if underestimated. Moreover, the study showed that elastic deformation in one zone can lead to inelastic deformation in the same zone.

Fatigue Life Comparison of Modified and Conventional 3 Leg Jacket Offshore Structure

The jacket structure must be adapted to the conditions of the production field to support economic factors. So, the concept of a modular platform for minimal, low-cost facilities is adopted. However, the design differences will affect the performance of the jacket itself, in other words a modular jacket can withstand the same load as a conventional jacket model but has a different structural performance. Therefore, this research discusses the performance comparison, which includes the fatigue life and the natural period, between conventional and modular jacket structures, which in this study are referred to as modified jackets. Conventional jacket as a comparison structure takes the design basis of the modified structure, including the same structural profiles, and environmental loads. In this study, the two jackets will only be modeled on the jacket part and the superstructure will be modeled as a joint load on the three upper ends of the jacket legs. Fatigue life analysis in this study used the full spectral analysis method. By using SACS software, the natural period of modified jacket is 1.756 s and conventional jacket is 1.472 s. While the lowest fatigue life on modified jacket is 44.98 years and conventional jacket is 9125.79 years.

Subspace Energy Monitoring for Anomaly Detection @Sensor or @Edge

The amount of data generated by distributed monitoring systems that can be exploited for anomaly detection, along with real time, bandwidth, and scalability requirements leads to the abandonment of centralized approaches in favor of processing closer to where data are generated. This increases the interest in algorithms coping with the limited computational resources of gateways or sensor nodes. We here propose two dual and lightweight methods for anomaly detection based on generalized spectral analysis. We monitor the signal energy laying along with the principal and anti -principal signal subspaces, and call for an anomaly when such energy changes significantly with respect to normal conditions. A streaming approach for the online estimation of the needed subspaces is also proposed. The methods are tested by applying them to synthetic data and real-world sensor readings. The synthetic setting is used for design space exploration and highlights the tradeoff between accuracy and computational cost. The real-world example deals with structural health monitoring and shows how, despite the extremely low computations costs, our methods are able to detect permanent and transient anomalies that would classically be detected by full spectral analysis.

Assessment of the Higher‐Order Structure of Formulated Monoclonal Antibody Therapeutics by 2D Methyl Correlated NMR and Principal Component Analysis

Characterization of the higher-order structure (HOS) of protein therapeutics, and in particular of monoclonal antibodies, by 2D 1 H-13 C methyl correlated NMR has been demonstrated as precise and robust. Such characterization can be greatly enhanced when collections of spectra are analyzed using multivariate approaches such as principal component analysis (PCA), allowing for the detection and identification of small structural differences in drug substance that may otherwise fall below the limit of detection of conventional spectral analysis. A major limitation to this approach is the presence of aliphatic signals from formulation or excipient components, which result in spectral interference with the protein signal of interest; however, the recently described Selective Excipient Reduction and Removal (SIERRA) filter greatly reduces this issue. Here we will outline how basic 2D 1 H-13 C methyl-correlated NMR may be combined with the SIERRA approach to collect 'clean' NMR spectra of formulated monoclonal antibody therapeutics (i.e., drug substance spectra free of interfering component signals), and how series of such spectra may be used for HOS characterization by direct PCA of the series spectral matrix. © 2020 U.S. Government. Basic Protocol 1: NMR data acquisition Basic Protocol 2: Full spectral matrix data processing and analysis Support Protocol: Data visualization and cluster analysis.

Unraveling nonlinear electrophysiologic processes in the human visual system with full dimension spectral analysis

Natural sensory signals have nonlinear structures dynamically composed of the carrier frequencies and the variation of the amplitude (i.e., envelope). How the human brain processes the envelope information is still poorly understood, largely due to the conventional analysis failing to quantify it directly. Here, we used a recently developed method, Holo-Hilbert spectral analysis, and steady-state visually evoked potential collected using electroencephalography (EEG) recordings to investigate how the human visual system processes the envelope of amplitude-modulated signals, in this case with a 14 Hz carrier and a 2 Hz envelope. The EEG results demonstrated that in addition to the fundamental stimulus frequencies, 4 Hz amplitude modulation residing in 14 Hz carrier and a broad range of carrier frequencies covering from 8 to 32 Hz modulated by 2 Hz amplitude modulation are also found in the two-dimensional frequency spectrum, which have not yet been recognized before. The envelope of the stimulus is also found to dominantly modulate the response to the incoming signal. The findings thus reveal that the electrophysiological response to amplitude-modulated stimuli is more complex than could be revealed by, for example, Fourier analysis. This highlights the dynamics of neural processes in the visual system.

Quasars as standard candles II

A tight non-linear relation between the X-ray and the optical-ultraviolet (UV) emission has been observed in active galactic nuclei (AGN) over a wide range of redshift and several orders of magnitude in luminosity, suggesting the existence of an ubiquitous physical mechanism regulating the energy transfer between the accretion disc and the X-ray emitting corona. Recently, our group developed a method to use this relation in observational cosmology, turning quasars into standardizable candles. This work mainly seeks to investigate the potential evolution of this correction at high redshifts. We thus studied the LX − LUV relation for a sample of quasars in the redshift range 4 < z < 7, adopting the selection criteria proposed in our previous work regarding their spectral properties. The resulting sample consists of 53 type 1 (unobscured) quasars, observed either with Chandra or XMM-Newton, for which we performed a full spectral analysis, determining the rest-frame 2 keV flux density, as well as more general X-ray properties such as the estimate of photon index, and the soft (0.5–2 keV) and hard (2–10 keV) unabsorbed luminosities. We find that the relation shows no evidence for evolution with redshift. The intrinsic dispersion of the LX–LUV for a sample free of systematics/contaminants is of the order of 0.22 dex, which is consistent with previous estimates from our group on quasars at lower redshift.

Analysis of the Acoustically Noise Situation in an Urbanized Area in the Presence of Vehicular and Industrial Noise

Acoustic noise is now becoming one of the important problems of the technosphere. The source of such noise in the streets of large cities is mainly motor transport, as well as industrial enterprises located in the city and construction sites. In the report some results of monitoring of acoustic pollution of the big industrially developed cities (on the example of the city of Murom) are considered. Monitoring is carried out with the help of a combined ecology-meteorological system. The measurement errors due to the standard octave analysis procedure with a control at central weighted frequencies are analyzed. It is shown that the application of the full spectral analysis using the fast Fourier transform allows us to compensate for these errors. The features of the construction of the measuring channel used in the monitoring procedure are considered. Some results of analysis of the spectrum and levels of acoustic noise on the streets of the city at different periods of the day are given. It is shown that in the most heavily loaded areas of the city, combining the activity of traffic flows and the functioning of industrial enterprises, the maximum values of sound pressure level of acoustic noise can reach 100 dB. Both maximum and average values of sound pressure are analyzed from the point of view of their compliance with the current sanitary norms. The conclusion is made that the actual noise levels exceed the maximum permissible levels for open spaces.