scholarly journals Comparison of annual changes of zenith tropospheric delay components, calculated according to the atmospheric sounding data and by analytical model

2021 ◽  
Vol 41 (I) ◽  
pp. 46-54
Author(s):  
B. KLADOCHNYI ◽  
◽  
B. PALIANYTSIA ◽  
Keyword(s):  
Analytical Model ◽  
Standard Error ◽  
Calculated Data ◽  
Analytical Models ◽  
Practical Significance ◽  
Tropospheric Delay ◽  
Annual Fluctuation ◽  
Near Surface ◽  
Zenith Tropospheric Delay ◽  
Atmospheric Sounding

The aim of this work is to study the zenith tropospheric delay components fluctuations according to the atmospheric sounding data and analytical model in selected period and accuracy assessment of Saastamoinen model. Methodology. The main methods for calculation ZTD are atmospheric sounding and using analytical models. To study ZTD components we use atmospheric sounding data conducted at 4 Ukrainian upper air stations (Kyiv, Kharkiv, Lviv, Odesa) with 24 hours frequency, as well as near-surface atmospheric variables provided by weather stations with 3 hours frequency in the period from January 1 to December 31, 2019. ZTD components were calculated by integration using sounding data, and using Saastamoinen’s formulas. Based on the calculated data, created graphs comparing the values of sounding and model. Calculated the standard error of Saastamoinen model. Results. Compared ZTD components at points, located in different climatic zones, using the atmospheric pressure reduced to sea level. Both ZDD and ZWD are the largest at Odesa station. Annual fluctuation of ZDD are 8–20 mm and ZWD fluctuations are 75–95 mm. The daily amplitudes of ZDD are 5–6 mm in summer and 12–13 mm in winter. The daily amplitudes of ZWD are 20–30 mm in summer and 6–8 mm in winter. The standard error of Saastamoinen’s model is 7 mm for ZDD and 22 mm for ZWD. Scientific novelty and practical significance in that the study can improve accuracy and evaluate the feasibility of using different methods for calculating ZTD, see the dynamic of change ZDD and ZWD and their behavior over a long period. The results can be used for further studies of ZTD and improving the accuracy of satellite observations.

scholarly journals GEODESY, CARTOGRAPHY AND AERIAL PHOTOGRAPHY

2020 ◽  
Vol 92,2020 (92) ◽  
pp. 5-14
Author(s):  
B. B. Palianytsia ◽  
◽  
B. V. Kladochnyi ◽  
Kh. B. Palianytsia ◽  
◽  
...  
Keyword(s):  
Weather Conditions ◽  
Practical Significance ◽  
Hydraulic Structures ◽  
Tropospheric Delay ◽  
Annual Change ◽  
Total Delay ◽  
Annual Average ◽  
Monthly Average ◽  
Zenith Tropospheric Delay ◽  
Annual Period

The aim of this work is to study the fluctuations of the components of the zenith tropospheric delay during the annual period according to the ground meteorological measurements in Ukraine. Methodolodgy. The surface values of meteorological values at the stations: Lviv, Kyiv, Kharkiv and Odesa, obtained in 2019 with an interval of 3 hours were used for the research. A total amount of 2020 measurements at each of the stations has been presented. The calculation of the components of the zenith tropospheric delay was performed according to the Saastamoinen formula. According to the calculated values of the components, graphs of changes in the dry and wet components of the zenith tropospheric delay for each of the stations during constructed. Subsequently, the monthly average and annual average values of the components were calculated and compared with each other. Results. Based on studies of changes in delay values at four Ukrainian meteorological stations for the period of 2019, it was found that the monthly average values of ZHD component are higher at stations whose altitude is lower. The wet component of ZWD during the year acquires the biggest values in summer. Annual fluctuations of the dry component of ZHD have a much smaller amplitude than the wet ZWD. The amplitude of the change in the total delay is determined by the amplitude of the change of the wet component, which at different stations is almost two times bigger than the amplitude of the change of the dry component, although ZWD is only up to 10% of ZTD. Thus, the variations in the total tropospheric delay, which indirectly reflects the weather and climatic processes due to variations in the wet component. Scientific novelty and practical significance consist in identifying the features of the annual change in the components of tropospheric delay at stations in different climatic and weather conditions. The performed research can be used in the tasks of monitoring of large hydraulic structures by GNSS methods to create regional models of the atmosphere and further studies of tropospheric delay, as they relate to its changes in space and time.

scholarly journals GEODESY, CARTOGRAPHY, AND AERIAL PHOTOGRAPHY

2021 ◽  
Vol 93,2021 (93) ◽  
pp. 48-58
Author(s):  
Bohdan Palianytsia ◽  
◽  
Bohdan Kladochnyi ◽  
Oksana Palianytsia ◽  
◽  
...  
Keyword(s):  
Initial Step ◽  
3D Models ◽  
Practical Significance ◽  
Tropospheric Delay ◽  
Detailed Model ◽  
Component Distribution ◽  
Zenith Tropospheric Delay ◽  
Moment Distribution ◽  
Graphic Editor ◽  
Spatio Temporal

The purpose of this work is to build 3D models of components of zenith tropospheric delay (ZTD) according to the surface measurements of meteorological values obtained at 100 points, which is almost evenly distributed throughout Ukraine. Method. Saastamoinen formulas calculated dry and wet components of the zenith tropospheric delay. According to the obtained results, the fields of dry and wet components of tropospheric delay were compiled, the fields of their change were constructed using a different number of studied points. Also, with the help of a graphic editor, 3D models of the magnitude one-moment distribution of dry and wet components of the zenith tropospheric delay for the territory of Ukraine were built. Results. Built 3D models of ZTD components; constructed zenith tropospheric delay fields for the territory of Ukraine; a comparison of the distribution of delay components for the specified area and its change during the day are the results of this work. It is established that the dry component becomes more important in the southern and central territory of Ukraine, where the observation points are lower in height and where there is a higher atmospheric pressure, which dominates in the calculation of this component. Accordingly, the wet component is also higher in the southern part of Ukraine, but this is due to higher relative humidity. As a result of the compaction of the network to 100 points, more accurate models of component distribution were obtained, which allowed Ukraine to assess in more detail the value of tropospheric delay for the territory of Ukraine. Further compaction of the network for the territory of Ukraine did not lead to the expected increase in the accuracy of tropospheric delay, as the location of meteorological stations in the country is not uniform enough, and some values of meteorological magnitudes are obtained not by direct measurements but by interpolation. It is necessary to compact the model with reliable meteorological measurements evenly and to control the calculation of components by integrating according to the aerological soundings carried out at individual points to obtain a more detailed model. Scientific novelty and practical significance. The scientific novelty is to build 3D models of tropospheric delay components for the territory of Ukraine at a certain point in time. The practical significance of the performed research is that they can be used as an initial step to build a Spatio-temporal model of tropospheric delay, reflecting the spatial changes of the delay in real-time for a particular area.

scholarly journals Regional Zenith Tropospheric Delay Modeling Based on Least Squares Support Vector Machine Using GNSS and ERA5 Data

2021 ◽  
Vol 13 (5) ◽  
pp. 1004
Author(s):  
Song Li ◽  
Tianhe Xu ◽  
Nan Jiang ◽  
Honglei Yang ◽  
Shuaimin Wang ◽  
...  
Keyword(s):  
Support Vector Machine ◽  
Least Squares ◽  
High Efficiency ◽  
Rapid Development ◽  
Support Vector ◽  
Tropospheric Delay ◽  
Improvement Rate ◽  
Zenith Tropospheric Delay ◽  
Background Data ◽  
Mean Square Errors

The meteorological reanalysis data has been widely applied to derive zenith tropospheric delay (ZTD) with a high spatial and temporal resolution. With the rapid development of artificial intelligence, machine learning also begins as a high-efficiency tool to be employed in modeling and predicting ZTD. In this paper, we develop three new regional ZTD models based on the least squares support vector machine (LSSVM), using both the International GNSS Service (IGS)-ZTD products and European Centre for Medium-Range Weather Forecasts Reanalysis 5 (ERA5) data over Europe throughout 2018. Among them, the ERA5 data is extended to ERA5S-ZTD and ERA5P-ZTD as the background data by the model method and integral method, respectively. Depending on different background data, three schemes are designed to construct ZTD models based on the LSSVM algorithm, including the without background data, with the ERA5S-ZTD, and with the ERA5P-ZTD. To investigate the advantage and feasibility of the proposed ZTD models, we evaluate the accuracy of two background data and three schemes by segmental comparison with the IGS-ZTD of 85 IGS stations in Europe. The results show that the overall average Root Mean Square Errors (RMSE) value of all sites is 30.1 mm for the ERA5S-ZTD, and 10.7 mm for the ERA5P-ZTD. The overall average RMSE is 25.8 mm, 22.9 mm, and 9 mm for the three schemes, respectively. Moreover, the overall improvement rate is 19.1% and 1.6% for the ZTD model with ERA5S-ZTD and ERA5P-ZTD, respectively. In order to explore the reason of the lower improvement for the ZTD model with ERA5P-ZTD, the loop verification is performed by estimating the ZTD values of each available IGS station. In actuality, the monthly improvement rate of estimated ZTD is positive for most stations, and the biggest improvement rate can even reach about 40%. The negative rate mainly comes from specific stations, these stations are located on the edge of the region, near the coast, as well as the lower similarity between the individual verified station and training stations.

scholarly journals Novel Structure and Thermal Design and Analysis for CubeSats in Formation Flying

Aerospace ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 150
Author(s):  
Yeon-Kyu Park ◽  
Geuk-Nam Kim ◽  
Sang-Young Park
Keyword(s):  
Analytical Model ◽  
Formation Flying ◽  
Thermal Environment ◽  
Thermal Analyses ◽  
Thermal Design ◽  
Analytical Models ◽  
Test Results ◽  
Solar Panels ◽  
Novel Structure ◽  
Micro Propulsion

The CANYVAL-C (CubeSat Astronomy by NASA and Yonsei using a virtual telescope alignment for coronagraph) is a space science demonstration mission that involves taking several images of the solar corona with two CubeSats—1U CubeSat (Timon) and 2U CubeSat (Pumbaa)—in formation flying. In this study, we developed and evaluated structural and thermal designs of the CubeSats Timon and Pumbaa through finite element analyses, considering the nonlinearity effects of the nylon wire of the deployable solar panels installed in Pumbaa. On-orbit thermal analyses were performed with an accurate analytical model for a visible camera on Timon and a micro propulsion system on Pumbaa, which has a narrow operating temperature range. Finally, the analytical models were correlated for enhancing the reliability of the numerical analysis. The test results indicated that the CubeSats are structurally safe with respect to the launch environment and can activate each component under the space thermal environment. The natural frequency of the nylon wire for the deployable solar panels was found to increase significantly as the wire was tightened strongly. The conditions of the thermal vacuum and cycling testing were implemented in the thermal analytical model, which reduced the differences between the analysis and testing.

scholarly journals A New Zenith Tropospheric Delay Grid Product for Real-Time PPP Applications over China

Sensors ◽  
2017 ◽  
Vol 18 (2) ◽  
pp. 65 ◽  
Author(s):  
Yidong Lou ◽  
Jinfang Huang ◽  
Weixing Zhang ◽  
Hong Liang ◽  
Fu Zheng ◽  
...  
Keyword(s):  
Real Time ◽  
Tropospheric Delay ◽  
Zenith Tropospheric Delay

Near Surface Research and Excitation Horizon Prediction Based on Old River Course of Xiaoqing River in Shan Dong

2013 ◽  
Vol 664 ◽  
pp. 94-98
Author(s):  
Guang De Zhang
Keyword(s):  
Seismic Data ◽  
Practical Significance ◽  
Cone Penetration ◽  
Surface Deposition ◽  
Near Surface ◽  
Sedimentary Characteristics ◽  
The Difference ◽  
Exploration Area ◽  
Data Requirements ◽  
Static Cone Penetration Test

Following deepened exploration and development in Shengli exploration area, seismic data requirements are also getting higher and higher. However, in recent years the difference of Xiaoqing river on both sides have made us know that the importance of this problem. In view of the above, this task is aimed at quaternary shallow of old river course within Xiaoqing River. Our analysis of lithology and sedimentary characteristics are using static cone penetration test and rock core exploration method, and we want to reappear near surface deposition of old river course within Xiaoqing River. The research is close combined with the exploration demand and theoretical study, so it has important theoretical and practical significance.

The effects of geometric offsets on the dynamic responses of a Scott—Russell amplifying mechanism with flexible hinges

2009 ◽  
Vol 223 (10) ◽  
pp. 2413-2423 ◽  
Author(s):  
C-M Chen ◽  
R-F Fung
Keyword(s):  
Numerical Simulations ◽  
Analytical Model ◽  
Dynamic Responses ◽  
Analytical Models ◽  
Dynamic Equations ◽  
Magnification Factor ◽  
Flexure Hinges ◽  
Magnification Factors ◽  
Straight Line ◽  
Deviation Factor

The dynamic equations of a micro-positioning Scott—Russell (SR) mechanism associated with two flexible hinges and an offset are developed to calculate output responses. Both rigid and flexible hinges are considered to explore the results. The main features in the kinematics of the SR mechanism are its displacement amplification and straight-line motion, which are widely needed in practical industries. The manufacturing inaccuracy of the SR mechanism definitely causes geometric offsets of flexure hinges, and affects displacement amplification and straight-line output motion. Analytical models based on kinematics and Hamilton's principle are derived to explore the variation of linearity ratio, magnification factor, and deviation factor due to various offsets and link lengths. From numerical simulations for the SR mechanism with various offsets of flexible hinges in the conditions of different link lengths, it is found that offsets of flexure hinges obviously affect the amplifying factor and linearity ratio, and appear to dominate the changes of magnification factors. Moreover, an analytical model is also used to predict magnification factors due to various offsets. Finally, some conclusions concerning the effects of offset on the performance of the SR mechanism are drawn.

Ефективність інноваційної діяльності харчової промисловості в системі цілей сталого розвитку країни

Ekonomika APK ◽  
2021 ◽  
Vol 319 (5) ◽  
pp. 46-56
Author(s):  
Olha Kovalenko ◽  
Liudmyla Yashchenko
Keyword(s):  
Sustainable Development ◽  
Capital Investment ◽  
Food Industry ◽  
Methodological Approach ◽  
Calculated Data ◽  
Weighted Average ◽  
Practical Significance ◽  
Educational Institutions ◽  
The Sustainable Development ◽  
Methodical Approach

The purpose of the article is to improve approaches to assessing the effectiveness of innovative activities of the food industry and its individual subsectors to identify prospects for development and problems that can hinder the sustainable development of this area of production and the country as a whole. Research methods. The article uses the methods of theoretical generalizations and comparisons, which made it possible to comprehensively consider and generalize methodological approaches to assessing the effectiveness of innovation in industries. When systematizing the calculated data by the intensity of innovation costs, the methods of statistical classification and grouping were used. To achieve the goal of the study, the methodology for assessing the level of manufacturability of industries has been improved (the OECD methodology is taken as a basis), which made it possible to re-evaluate the effectiveness of innovative activities in sub-sectors of the food industry with an emphasis on the computerization of production. Research results. The article presents a methodical approach to assessing the effectiveness of innovation in the food industry. The study is based on the OECD methodology for assessing the manufacturability of industries, which is to calculate the weighted average cost intensity of R & D. The application of this approach to the food industry has confirmed the too low level of its innovative manufacturability. It was found that due to the lack of relevant statistics on R&D expenditures, it is difficult to assess the effectiveness of innovation in certain sectors of the food industry. It is proposed to solve this problem with the help of capital investment indicators, which are invested in the software of industries and are directly related to the level of computerization of technological processes. The obtained indicators of the intensity of software costs are ranked in descending order and divided into three groups according to the level of computerization, which characterizes the efficiency of innovation, as its level increases profits and profitability in industries. This will contribute to the goals of sustainable development of the country (including goals 2 and 9) and increase the competitiveness of the food industry. Scientific novelty. A methodological approach to assessing the effectiveness of innovative activities of sub-sectors of the food industry in Ukraine is proposed, which will contribute to the formation of a new look at the research methodology of this area of knowledge. Practical significance. Designed for professionals in the field of food industry economics, scientists, teachers, graduate students and students of higher educational institutions. The results of the study can be used by experts to assess the level of manufacturability of industries. Tabl.: 3. Refs.: 30.

Modeling of residual stresses by correlating surface topography in machining of AISI 52100 steel

2021 ◽  
pp. 1-26
Author(s):  
Chao Liu ◽  
Yan He ◽  
Yufeng Li ◽  
Yulin Wang ◽  
Shilong Wang ◽  
...  
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Cutting Force ◽  
Surface Topography ◽  
Analytical Model ◽  
Analytical Models ◽  
Workpiece Surface ◽  
Dynamic Cutting Force ◽  
Intermittent Cutting ◽  
Effect Of Surface

Abstract The residual stresses could affect the ability of components to bear loading conditions and also the performance. The researchers considered workpiece surface as a plane and ignored the effect of surface topography induced by the intermittent cutting process when modeling residual stresses. The aim of this research develops an analytical model to predict workpiece residual stresses during intermittent machining by correlating the effect of surface topography. The relative motions of tool and workpiece are analyzed for modeling thermal-mechanical and surface topography. The influence of dynamic cutting force and thermal on different positions of surface topography is also considered in analytical model. Then the residual stresses model with the surface topography effect can be developed in intermittent cutting. The analytical models of dynamic cutting force, surface topography and residual stresses are verified by the experiments. The variation trend of evaluated values of the residual stress of workpiece is basically consistent with that of measured values. The compressive residual stress of workpiece surface in highest point of the surface topography are higher than that in the lowest point.

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