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oe1(光电查) - 科学论文

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出版时间
  • 2018
研究主题
  • spectral irradiance
  • correlated color temperature
  • double monochromator
  • color rendering index
  • Uncertainty of measurement
应用领域
  • Measurement and Control Technology and Instruments
机构单位
  • Brno University of Technology
149 条数据
?? 中文（中国） ▾

  • Quantification of uncertainty in aerosol optical thickness retrieval arising from aerosol microphysical model and other sources, applied to Ozone Monitoring Instrument (OMI) measurements

    摘要： Satellite instruments are nowadays successfully utilised for measuring atmospheric aerosol in many applications as well as in research. Therefore, there is a growing need for rigorous error characterisation of the measurements. Here, we introduce a methodology for quantifying the uncertainty in the retrieval of aerosol optical thickness (AOT). In particular, we concentrate on two aspects: uncertainty due to aerosol microphysical model selection and uncertainty due to imperfect forward modelling. We apply the introduced methodology for aerosol optical thickness retrieval of the Ozone Monitoring Instrument (OMI) on board NASA's Earth Observing System (EOS) Aura satellite, launched in 2004. We apply statistical methodologies that improve the uncertainty estimates of the aerosol optical thickness retrieval by propagating aerosol microphysical model selection and forward model error more realistically. For the microphysical model selection problem, we utilise Bayesian model selection and model averaging methods. Gaussian processes are utilised to characterise the smooth systematic discrepancies between the measured and modelled reflectances (i.e. residuals). The spectral correlation is composed empirically by exploring a set of residuals. The operational OMI multi-wavelength aerosol retrieval algorithm OMAERO is used for cloud-free, over-land pixels of the OMI instrument with the additional Bayesian model selection and model discrepancy techniques introduced here. The method and improved uncertainty characterisation is demonstrated by several examples with different aerosol properties: weakly absorbing aerosols, forest fires over Greece and Russia, and Sahara desert dust. The statistical methodology presented is general; it is not restricted to this particular satellite retrieval application.

    关键词： OMI,Gaussian processes,OMAERO,uncertainty quantification,Bayesian model selection,aerosol optical thickness

    更新于2025-09-23 15:22:29

  • Uncertainty budgets of major ozone absorption cross sections used in UV remote sensing applications

    摘要： Detailed uncertainty budgets of three major ultraviolet (UV) ozone absorption cross-section datasets that are used in remote sensing application are provided and discussed. The datasets are Bass–Paur (BP), Brion–Daumont–Malicet (BDM), and the more recent Serdyuchenko–Gorshelev (SG). For most remote sensing application the temperature dependence of the Huggins ozone band is described by a quadratic polynomial in temperature (Bass–Paur parameterization) by applying a regression to the cross-section data measured at selected atmospherically relevant temperatures. For traceability of atmospheric ozone measurements, uncertainties from the laboratory measurements as well as from the temperature parameterization of the ozone cross-section data are needed as input for detailed uncertainty calculation of atmospheric ozone measurements. In this paper the uncertainty budgets of the three major ozone cross-section datasets are summarized from the original literature. The quadratic temperature dependence of the cross-section datasets is investigated. Combined uncertainty budgets is provided for all datasets based upon Monte Carlo simulation that includes uncertainties from the laboratory measurements as well as uncertainties from the temperature parameterization. Between 300 and 330 nm both BDM and SG have an overall uncertainty of 1.5 %, while BP has a somewhat larger uncertainty of 2.1 %. At temperatures below about 215 K, uncertainties in the BDM data increase more strongly than the others due to the lack of very low temperature laboratory measurements (lowest temperature of BDM available is 218 K).

    关键词： uncertainty budgets,Monte Carlo simulation,temperature dependence,UV remote sensing,ozone absorption cross sections

    更新于2025-09-23 15:21:21

  • [IEEE 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Trebic, Czech Republic (2018.9.18-2018.9.20)] 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - The Uncertainty of Measurement of Spectroradiometric System with Double Monochromator

    摘要： This article has task to inform a reader about uncertainties of measurement of spectroradiometric systems with double monochromator. Uncertainty of measurement is very important for all photometric measurements and calculations. Spectroradiometric system’s uncertainty is dependent on wavelength and is difficult to estimate uncertainty of measurement for photometric parameters calculated from measured spectrum. In the first part of this article there is theory necessary for understanding uncertainty analyses and description of construction of spectroradiometric system with double monochromator. In the second part there is practical uncertainty analysis of double monochromator in light laboratory and its results.

    关键词： spectral irradiance,correlated color temperature,double monochromator,color rendering index,Uncertainty of measurement

    更新于2025-09-23 15:21:21

  • Tightening the entropic uncertainty relations for multiple measurements and applying it to quantum coherence

    摘要： The uncertainty principle sets limit on our ability to predict the values of two incompatible observables measured on a quantum particle simultaneously. This principle can be stated in various forms. In quantum information theory, it is expressed in terms of the entropic measures. Uncertainty bound can be altered by considering a particle as a quantum memory correlating with the primary particle. In this work, a method is provided for converting the entropic uncertainty relation in the absence of quantum memory to that in its presence. It is shown that the lower bounds obtained through the method are tighter than those having been achieved so far. The method is also used to obtain the uncertainty relations for multiple measurements in the presence of quantum memory. Also for a given state, the lower bounds on the sum of the relative entropies of unilateral coherences are provided using the uncertainty relations in the presence of quantum memory, and it is shown which one is tighter.

    关键词： Quantum memory,Entropic uncertainty relations,Quantum coherence,Multiple measurements

    更新于2025-09-23 15:21:21

  • [IEEE 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Rome, Italy (2019.6.17-2019.6.20)] 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Differentiation of the Laser Pulse in a Waveguide with a Bragg Grating

    摘要： A novel one-port probe technique, which combines the measurements of a rectangular waveguide and coaxial probe to nondestructively yield the permittivity and permeability of a PEC-backed material, is presented. A brief description of the derivation of the theoretical probe reflection coefficients, necessary for permittivity and permeability extraction via numerical inversion, is provided. Experimental characterization results of a PEC-backed magnetic material are presented to validate the proposed approach. Error analysis is also undertaken to quantify the new technique’s sensitivity to common experimental errors.

    关键词： moment methods,microwave measurements,waveguides,Integral equations,permeability measurement,uncertainty,permittivity measurement,measurement uncertainty

    更新于2025-09-23 15:21:01

  • [IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Revision of GUM: the suggested alhorythm for processing measurment results

    摘要： The main requirements for the revised GUM are considered. The proposed algorithm for processing measurement results is given. Criteria for compliance with the listed requirements are described. Methods for processing the measurement results with a nonlinear model are proposed.

    关键词： estimate and standard uncertainty of the measurand,estimates and standard uncertainties of input quantities,correlation,expanded uncertainty,GUM revision

    更新于2025-09-23 15:21:01

  • [IEEE 2020 3rd International Conference on Computing, Mathematics and Engineering Technologies (iCoMET) - Sukkur, Pakistan (2020.1.29-2020.1.30)] 2020 3rd International Conference on Computing, Mathematics and Engineering Technologies (iCoMET) - Maximum Power Extraction from Photovoltaic System using Integral Sliding Mode Control

    摘要： In this paper, an Integral Sliding Mode Control (ISMC) is presented to extract maximum power from photovoltaic (PV) system in the presence of uncertainties. The considered SISO system is affected by bounded uncertainty, which is directly effecting desire output of PV system. The main objective of this paper is to design such closed loop control system which can tolerate the uncertainty and make possible the maximum power extraction from PV system. Hence, ISMC is proposed as a robust control mechanism against these uncertainties. The efficiency of the presented concept is demonstrated in detail, using results of numerical simulations.

    关键词： PV system,Bounded uncertainty,MPPT,ISMC

    更新于2025-09-23 15:21:01

  • Data-driven uncertainty analysis of distribution networks including photovoltaic generation

    摘要： This paper investigates residential distribution networks with uncertain loads and photovoltaic distributed generation. An original probabilistic modeling of consumer demand and photovoltaic generation is presented that is based on the analysis of large set of data measurements. It is shown how photovoltaic generation is described by complex non-standard distributions that can be described only numerically. Probabilistic analysis is performed using an enhanced version of the Polynomial Chaos technique that exploits a proper set of polynomial basis functions. It is described how such functions can be generated from the numerically available data. Compared to other approximate methods for probabilistic analysis, the novel technique has the advantages of modeling accurately truly nonlinear problems and of directly providing the detailed Probability Density Function of relevant observable quantities affecting the quality of service. Compared to standard Monte Carlo method, the proposed technique introduces a simulation speedup that depends on the number of random parameters. Numerical applications to radial and weakly meshed networks are presented where the method is employed to explore overvoltage, unbalance factor and power loss, as a function of photovoltaic penetration and/or network configuration.

    关键词： Photovoltaic generation,Data-driven models,Polynomial chaos,Unbalanced distribution networks,Probabilistic load flow,Uncertainty Analysis

    更新于2025-09-23 15:21:01

  • [IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Evaluation of ultrasound reflection coefficient measurement result and its uncertainty by the method of linearization

    摘要： It is shown that, if the ultrasound amplitudes before (A0) and after(A) application of the test liquid (soybean oil) to the working surface of the acoustic cell are measured using only one (working) channel of the installation, the measurement results become mutually correlated. And if A0 is measured on the reference installation channel and the amplitude A is measured on the working channel of the installation, the measurement results are not mutually correlated. And thus, it becomes possible to use the method of linearization to evaluate the measurement result and its accuracy characteristics (error and / or uncertainty).

    关键词： error,uncertainty,ultrasound,acoustic cell,method of linearization,reference,liquid,measurement,working,correlation,reflection coefficient,soybean oil

    更新于2025-09-23 15:21:01

  • [IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Adaptation of the least squares method for determination of oscillating type measuring devices parameters with using gain-frequency characteristic

    摘要： In this article there is suggested a method, which determines both a time constant and a gain-frequency characteristic damp constant for a measuring device, which is simulated by oscillating type dynamic element. The described method is based on a method of least squares, which increases an identification accuracy because of obtaining more information about a measuring device performance during a measurement process. The standard uncertainties of both a time constant and a damp constant are analyzed. The recommendations for measuring process, which was mentioned above, optimization are given.

    关键词： standard uncertainty,gain-frequency characteristic,dynamic characteristic,measuring device,oscillating type dynamic element

    更新于2025-09-23 15:21:01