Accuracy Test of Laser Tracker under Condition of Air Turbulence

2017 ◽  
Author(s):  
Janusz Kwiecien
Keyword(s):  
Measurement Accuracy ◽  
Meteorological Parameters ◽  
Turbulence Structure ◽  
Laser Tracking ◽  
Accuracy Test ◽  
Air Turbulence ◽  
Laser Wave ◽  
Particulate Pollutants ◽  
Predicted Values ◽  
Linear Accuracy

Laser tracking for interior industrial metrology is discussed. In this work, the effects of air turbulence on the angle of laser wave propagation is analyzed in the absence of the effects associated with other meteorological parameters (pressure, humidity) and particulate pollutants (dust, smoke). This analysis establishes the effectiveness of laser tracking under turbulent air conditions and quantification of deviations in the angular and linear accuracy from those provided by the manufacturer. An experimental setup and associated measurement method to determine the turbulence structure coefficient are described. It was found that turbulent air conditions resulted in a radical decrease in measurement accuracy. The reduction in accuracy was evidenced by a decrease in power and an increase in standard deviation of the laser beam, as well as a decline in the angle and distance measurement precision. The experimental measurements show a high correlation to predicted values.

scholarly journals Fuzzy logic device for crop analysing, modeling and forecasting in the Kabardino-Balkarian Republic

2020 ◽  
Vol 15 (2) ◽  
pp. 123-133
Author(s):  
Ruslan M. Bischokov
Keyword(s):  
Meteorological Parameters ◽  
Crop Yields ◽  
Climatic Factors ◽  
Crop Productivity ◽  
Logic Device ◽  
Modeling And Forecasting ◽  
Expected Values ◽  
Predicted Values ◽  
Climatic Characteristics

Using computer fuzzy-logical models based on empirical values of climatic characteristics (rainfall, temperature and humidity) of long-term observations (1955-2018) from meteorological stations in the Kabardino-Balkarian Republic (Nalchik, Baksan, Prokhladny and Terek) and crop yields (winter wheat, spring wheat, corn, sunflower, millet, oats), dependence of crop yields on variations of climatic factors were analyzed and a specific forecast was given. Setting expected values of climatic characteristics in computer model, we received possible values of productivity for the next season. Uniformity assessment (Dixon and Smirnov - Grabbsas criterion), stability (Student and Fischers criterion), statistical importance of parameters of distribution and accidental errors were determined. Originality of the method is in the fact that in the form of input parameters of the model predictors, the previously calculated forecast values of the meteorological parameters for the next agricultural year were used, and at the output, the predicted values of crop productivity were obtained as predictants. Furthermore, recommendations on adoption of management decisions were developed.

scholarly journals Accuracy test of laser station under conditions of air turbulence

2017 ◽  
Vol 11 (3) ◽  
pp. 67
Author(s):  
Janusz Kwiecień ◽  
Adam Bujarkiewicz
Keyword(s):  
Accuracy Test ◽  
Air Turbulence

scholarly journals Temporal Variability of Equivalent Black Carbon Components in Atmospheric Air in Southern Poland

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 119
Author(s):  
Natalia Zioła ◽  
Barbara Błaszczak ◽  
Krzysztof Klejnowski
Keyword(s):  
Black Carbon ◽  
Fossil Fuels ◽  
Meteorological Parameters ◽  
Correlation Coefficients ◽  
Fossil Fuel Combustion ◽  
Southern Poland ◽  
Particulate Pollutants ◽  
Ambient Concentrations ◽  
High Concentrations

This study assesses the air quality in Zabrze (southern Poland) based on the ambient concentrations of equivalent black carbon (eBC). eBC measurement campaigns were carried out from April 2019 to March 2020 using a modern AE33 Aethalometer, accompanied by parallel measurements of gaseous pollutants, PM10 and meteorological parameters. The use of the two-component AE33 model allows for the determination of the eBC from fossil fuel combustion (eBCff) and biomass burning (eBCbb). The obtained results showed a clear seasonal variability of eBC concentrations, with higher average levels in the heating season (4.70 µg·m−3) compared to the non-heating one (1.79 µg·m−3). In both seasons, the eBCff component had a dominant share in total eBC, which indicates significant emissions from the combustion of fossil fuels for heating purposes and from local traffic sources. The obtained results showed high correlation coefficients with gaseous and particulate pollutants, with the strongest relationship for eBC and carbon monoxide (CO). During the non-heating and heating period, both anticyclone and cyclone systems played an important role in shaping eBC, eBCff and eBCbb concentrations. High concentrations of all components occurred with a significant decrease in air temperature and solar radiation in winter.

scholarly journals Air quality over Europe: modelling gaseous and particulate pollutants

2013 ◽  
Vol 13 (18) ◽  
pp. 9661-9673 ◽  
Author(s):  
E. Tagaris ◽  
R. E. P. Sotiropoulou ◽  
N. Gounaris ◽  
S. Andronopoulos ◽  
D. Vlachogiannis
Keyword(s):  
Air Quality ◽  
Western Europe ◽  
Anthropogenic Emissions ◽  
Southern Europe ◽  
Mixing Ratios ◽  
Particulate Pollutants ◽  
Predicted Values ◽  
Eastern And Western Europe ◽  
Modelling System ◽  
Good Agreement

Abstract. Air quality over Europe using Models-3 (i.e., CMAQ, MM5, SMOKE) modelling system is performed for winter (i.e., January 2006) and summer (i.e., July 2006) months with the 2006 TNO gridded anthropogenic emissions database. Higher ozone mixing ratios are predicted in southern Europe while higher NO2 levels are simulated over western Europe. Elevated SO2 values are simulated over eastern Europe and higher PM2.5 concentrations over eastern and western Europe. Regional average results suggest that NO2 and PM2.5 are underpredicted, SO2 is overpredicted, while Max8hrO3 is overpredicted for low mixing ratios and is underpredicted for the higher mixing ratios. However, in a number of countries observed and predicted values are in good agreement for the pollutants examined here. Speciated PM2.5 components suggest that NO3 is dominant during winter over western Europe and in a few eastern countries due to the high NO2 mixing ratios. During summer NO3 is dominant only in regions with elevated NH3 emissions. For the rest of the domain SO4 is dominant. Low OC concentrations are simulated mainly due to the uncertain representation of SOA formation.

scholarly journals Spatiotemporal Variations of Particulate and Gaseous Pollutants and Their Relations to Meteorological Parameters: The Case of Xiangyang, China

2019 ◽  
Vol 17 (1) ◽  
pp. 136
Author(s):  
Wei Xue ◽  
Qingming Zhan ◽  
Qi Zhang ◽  
Zhonghua Wu
Keyword(s):  
Air Quality ◽  
Wind Speed ◽  
Relative Humidity ◽  
Air Pollutants ◽  
Meteorological Parameters ◽  
Air Pollutant ◽  
Weekend Effect ◽  
Gaseous Pollutants ◽  
Statistical Point ◽  
Particulate Pollutants

High air pollution levels have become a nationwide problem in China, but limited attention has been paid to prefecture-level cities. Furthermore, different time resolutions between air pollutant level data and meteorological parameters used in many previous studies can lead to biased results. Supported by synchronous measurements of air pollutants and meteorological parameters, including PM2.5, PM10, total suspended particles (TSP), CO, NO2, O3, SO2, temperature, relative humidity, wind speed and direction, at 16 urban sites in Xiangyang, China, from 1 March 2018 to 28 February 2019, this paper: (1) analyzes the overall air quality using an air quality index (AQI); (2) captures spatial dynamics of air pollutants with pollution point source data; (3) characterizes pollution variations at seasonal, day-of-week and diurnal timescales; (4) detects weekend effects and holiday (Chinese New Year and National Day holidays) effects from a statistical point of view; (5) establishes relationships between air pollutants and meteorological parameters. The principal results are as follows: (1) PM2.5 and PM10 act as primary pollutants all year round and O3 loses its primary pollutant position after November; (2) automobile manufacture contributes to more particulate pollutants while chemical plants produce more gaseous pollutants. TSP concentration is related to on-going construction and road sprinkler operations help alleviate it; (3) an unclear weekend effect for all air pollutants is confirmed; (4) celebration activities for the Chinese New Year bring distinctly increased concentrations of SO2 and thereby enhance secondary particulate pollutants; (5) relative humidity and wind speed, respectively, have strong negative correlations with coarse particles and fine particles. Temperature positively correlates with O3.

scholarly journals Research on Measurement Accuracy of Laser Tracking System Based on Spherical Mirror with Rotation Errors of Gimbal Mount Axes

2018 ◽  
Vol 18 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Zhaoyao Shi ◽  
Huixu Song ◽  
Hongfang Chen ◽  
Yanqiang Sun
Keyword(s):  
Measurement Error ◽  
Measurement Accuracy ◽  
Optical Axis ◽  
Tracking System ◽  
Vertical Direction ◽  
Laser Ranging ◽  
Spherical Mirror ◽  
Laser Tracking ◽  
Radial Error ◽  
Error Motion

Abstract This paper presents a novel experimental approach for confirming that spherical mirror of a laser tracking system can reduce the influences of rotation errors of gimbal mount axes on the measurement accuracy. By simplifying the optical system model of laser tracking system based on spherical mirror, we can easily extract the laser ranging measurement error caused by rotation errors of gimbal mount axes with the positions of spherical mirror, biconvex lens, cat’s eye reflector, and measuring beam. The motions of polarization beam splitter and biconvex lens along the optical axis and vertical direction of optical axis are driven by error motions of gimbal mount axes. In order to simplify the experimental process, the motion of biconvex lens is substituted by the motion of spherical mirror according to the principle of relative motion. The laser ranging measurement error caused by the rotation errors of gimbal mount axes could be recorded in the readings of laser interferometer. The experimental results showed that the laser ranging measurement error caused by rotation errors was less than 0.1 μm if radial error motion and axial error motion were within ±10 μm. The experimental method simplified the experimental procedure and the spherical mirror could reduce the influences of rotation errors of gimbal mount axes on the measurement accuracy of the laser tracking system.

Multiwavelength differential absorption lidar to improve measurement accuracy: test with ammonia over a traffic area

2018 ◽  
Vol 124 (7) ◽  
Author(s):  
Riccardo Rossi ◽  
Jean-François Ciparisse ◽  
Andrea Malizia ◽  
Michela Gelfusa ◽  
Pasquale Gaudio
Keyword(s):  
Measurement Accuracy ◽  
Differential Absorption ◽  
Differential Absorption Lidar ◽  
Accuracy Test ◽  
Traffic Area ◽  
Improve Measurement

Methods for Restricting Maximum Exposure Rate in Computerized Adaptative Testing

Methodology ◽  
2007 ◽  
Vol 3 (1) ◽  
pp. 14-23 ◽  
Author(s):  
Juan Ramon Barrada ◽  
Julio Olea ◽  
Vicente Ponsoda
Keyword(s):  
Measurement Accuracy ◽  
Computerized Adaptive Testing ◽  
Computation Time ◽  
Adaptive Testing ◽  
Exposure Rate ◽  
Control Parameters ◽  
The Impact ◽  
Two Alternatives ◽  
Selection Of ◽  
Maximum Exposure

Abstract. The Sympson-Hetter (1985) method provides a means of controlling maximum exposure rate of items in Computerized Adaptive Testing. Through a series of simulations, control parameters are set that mark the probability of administration of an item on being selected. This method presents two main problems: it requires a long computation time for calculating the parameters and the maximum exposure rate is slightly above the fixed limit. Van der Linden (2003) presented two alternatives which appear to solve both of the problems. The impact of these methods in the measurement accuracy has not been tested yet. We show how these methods over-restrict the exposure of some highly discriminating items and, thus, the accuracy is decreased. It also shown that, when the desired maximum exposure rate is near the minimum possible value, these methods offer an empirical maximum exposure rate clearly above the goal. A new method, based on the initial estimation of the probability of administration and the probability of selection of the items with the restricted method ( Revuelta & Ponsoda, 1998 ), is presented in this paper. It can be used with the Sympson-Hetter method and with the two van der Linden's methods. This option, when used with Sympson-Hetter, speeds the convergence of the control parameters without decreasing the accuracy.

Influence of stable iodine on the uptake of the thyroid – model vs. experiment

2001 ◽  
Vol 40 (01) ◽  
pp. 31-37 ◽  
Author(s):  
U. Wellner ◽  
E. Voth ◽  
H. Schicha ◽  
K. Weber
Keyword(s):  
Time Course ◽  
Compartment Model ◽  
The Body ◽  
Iodine Uptake ◽  
Model Calculations ◽  
Physiological Conditions ◽  
Iodine Supply ◽  
Predicted Values ◽  
The Individual ◽  
Stable Iodine

Summary Aim: The influence of physiological and pharmacological amounts of iodine on the uptake of radioiodine in the thyroid was examined in a 4-compartment model. This model allows equations to be derived describing the distribution of tracer iodine as a function of time. The aim of the study was to compare the predictions of the model with experimental data. Methods: Five euthyroid persons received stable iodine (200 μg, 10 mg). 1-123-uptake into the thyroid was measured with the Nal (Tl)-detector of a body counter under physiological conditions and after application of each dose of additional iodine. Actual measurements and predicted values were compared, taking into account the individual iodine supply as estimated from the thyroid uptake under physiological conditions and data from the literature. Results: Thyroid iodine uptake decreased from 80% under physiological conditions to 50% in individuals with very low iodine supply (15 μg/d) (n = 2). The uptake calculated from the model was 36%. Iodine uptake into the thyroid did not decrease in individuals with typical iodine supply, i.e. for Cologne 65-85 μg/d (n = 3). After application of 10 mg of stable iodine, uptake into the thyroid decreased in all individuals to about 5%, in accordance with the model calculations. Conclusion: Comparison of theoretical predictions with the measured values demonstrated that the model tested is well suited for describing the time course of iodine distribution and uptake within the body. It can now be used to study aspects of iodine metabolism relevant to the pharmacological administration of iodine which cannot be investigated experimentally in humans for ethical and technical reasons.

Structured methods for improving flow measurement accuracy in pipelines

2020 ◽  
pp. 30-35
Author(s):  
Gurami N. Akhobadze
Keyword(s):  
Flow Measurement ◽  
Measurement Accuracy ◽  
Directional Coupler ◽  
Signal To Noise Ratio ◽  
Scattered Wave ◽  
Orthogonal Polarization ◽  
Flow Sensors ◽  
Information Signal ◽  
Mass Flows ◽  
Processing Device

In the age of digital transformation of production processes in industry and science the development and design of intelligent flow sensors for granular and liquid substances transferring through pipelines becomes more important. With this in view new approaches for improving the accuracy of microwave flowmeters are proposed. Taking into account the characteristics ofelectromagnetic waves propagating through a pipeline, a wave scattered by inhomogeneities of the controlled medium is analyzed. Features of the transformation of the polarized scattered wave limiting the geometric dimensions of the pipeline and optimizing the values of the useful scattered signal are revealed. Expediency of collection of the information signal with orthogonal polarization of the scattered wave and through a directional coupler is substantiated. The method of estimating the measurement accuracy with reference to the signal-to-noise ratio at the input of the processing device is given. The research results can be used in cryogenic machine engineering to measure volume and mass flows of liquid cryogenic products.

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