检索结果-南通市图书馆

Evaluation of surface temperature and pressure derived from MERRA-2 and ERA5 reanalysis datasets and their applications in hourly GNSS precipitable water vapor retrieval over China

引用

Geodesy and Geodynamics 2023年第2期14卷 111-120页

作者： Liangke Huang Xiaoyang Fang Tengxu Zhang Haoyu Wang Lei Cui Lilong Liu College of Geomatics and geoinformation Guilin University of TechnologyGuilin 541006China School of Resources and Environmental Science and Engineering Hubei University of Science and TechnologyXianning 437100China

Temperature and pressure play key roles in Global Navigation Satellite System(GNSS) precipitable water vapor(PWV) retrieval. The National Aeronautics and Space Administration(NASA) and European Center for Medium-Range Weather Forecasts(ECMWF) have released their latest reanalysis product: the modern-era retrospective analysis for research and applications, version 2(MERRA-2) and the fifthgeneration ECMWF reanalysis(ERA5), respectively. Based on the reanalysis data, we evaluate and analyze the accuracy of the surface temperature and pressure products in China using the the measured temperature and pressure data from 609 ground meteorological stations in 2017 as reference *** the accuracy of the two datasets and their performances in estimating GNSS PWV are analyzed. The PWV derived from the pressure and temperature products of ERA5 and MERRA-2 has high accuracy. The annual average biases of pressure and temperature for ERA5 are-0.07 hPa and 0.45 K, with the root mean square error(RMSE) of 0.95 hPa and 2.04 K, respectively. The annual average biases of pressure and temperature for MERRA-2 are-0.01 hPa and 0.38 K, with the RMSE of 1.08 h Pa and 2.66 K, *** accuracy of ERA5 is slightly higher than that of MERRA-2. The two reanalysis data show negative biases in most regions of China, with the highest to lowest accuracy in the following order: the south,north, northwest, and Tibet Plateau. Comparing the GNSS PWV calculated using MERRA-2(GNSS MERRA-2 PWV) and ERA5(GNSS ERA5 PWV) with the radiosonde-derived PWV from 48 co-located GNSS stations and the measured PWV of the co-location radiosonde stations, it is found that the accuracy of GNSS ERA5 PWV is better than that of GNSS MERRA-2 PWV. These results show the different applicability of surface temperature and pressure products from MERRA-2 and ERA5 data, indicating that both have important applications in meteorological research and GNSS water vapor monitoring in China.

关键词： Temperature and pressure Global navigation satellite system Precipitable water vapor MERRA-2 ERA5

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Inversion of surface vegetation water content based on GNSS-IR and MODIS data fusion

引用

Satellite Navigation 2020年第1期1卷 230-244页

作者： Yalong Pan Chao Ren Yueji Liang Zhigang Zhang Yajie Shi College of Geomatics and geoinformation Guilin University of TechnologyGuilin 541006China research Center of Precise Engineering Surveying Guangxi Key Laboratory of Spatial Information and GeomaticsGuilin 541006China

Obtaining high-precision,long-term sequences of vegetation water content(VWC)is of great significance for assessing surface vegetation growth,soil moisture,and fire *** recent years,the global navigation satellite system-interferometric reflection(GNSS-IR)has become a new type of remote sensing technology with low cost,all-weather capability,and a high temporal *** has been widely used in the fields of snow depth,sea level,soil moisture content,and vegetation water *** normalized microwave reflectance index(NMRI)based on GNSS-IR technology has been proven to be effective in monitoring changes in *** paper considers the advantages and disadvantages of remote sensing technology and GNSS-IR technology in estimating VWC.A point-surface fusion method of GNSS-IR and MODIS data based on the GA-BP neural network is proposed to improve the accuracy of VWC *** vegetation index products(NDVI,GPP,LAI)and the NMRI that unified the temporal and spatial resolution were used as the input and output data of the training model,and the GA-BP neural network was used for training and ***,a spatially continuous NMRI product was *** a particular area of the United States as a research object,experiments show that(1)a neural network can realize the effective fusion of GNSS-IR and MODIS *** comparing the GA-BP neural network,BP neural network,and multiple linear regression(MLR),the three models fusion *** results show that the GA-BP neural network has the best modeling effect,and the r and RMSE between the model estimation result and the reference value are 0.778 and 0.0332,respectively;this network is followed by the BP neural network,in which the r and RMSE are 0.746 and 0.0465,*** has the poorest effect,with r and RMSE values of 0.500 and 0.0516,respectively.(2)The spatiotem-poral variation in the 16 days/500 m resolution NMRI product obtained by GA-BP neural network fusion is consistent with that

关键词： Vegetation water content GNSS-IR MODIS GA-BP Fusion Precision analysis

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A new method for coseismic offset detection from GPS coordinate time series

引用

Geodesy and Geodynamics 2023年第6期14卷 551-558页

作者： Zhiwei Yang Guangyu Xu Tengxu Zhang Mingkai Chen FeiWu Zhiping Chen School of Surveying and geoinformation Engineering East China University of TechnologyNanchang 330013China Key laboratory of Mine Environmental Monitoring and Improving around Poyang Lake of Ministry of Natural Resources East China University of TechnologyNanchang 330013China Key laboratory for Digital Land and Resources of Jiangxi Province East China University of TechnologyNanchang 330013China Hubei Luojia laboratory Wuhan 430079China College of Resources and Environmental Science and Engineering Hubei University of Science and TechnologyXianning 437100China

Currently,the extraction of coseismic offset signals primarily relies on earthquake catalog data to determine the occurrence time of *** is followed by the process of differencing the average GPS coordinate time series data,with a time interval of 3 to 5 days before and after the *** the face of the huge amount of GPS coordinate time series data today,the conventional approach of relying on earthquake catalog data to assist in obtaining coseismic offset signals has become increasingly *** address this problem,we propose a new method for automatically detecting coseismic offset signals in GPS coordinate time series without an extra earthquake catalog for ***,we pre-process the GPS coordinate time series data for filtering out stations with significant observations missing and detecting and removing ***,we eliminate other signals and errors in the GPS coordinate time series,such as trend and seasonal signals,leaving the coseismic offset signals as the primary *** resulting coordinate time series is then modeled using the first-order difference and data stacking *** modeling method enables automatic detection of the coseismic offset signals in the GPS coordinate time *** aforementioned method is applied to automatically detect coseismic offset signals using simulated data and the Searles Valley GPS data in California,*** results demonstrate the efficacy of our proposed method,successfully detecting coseismic offsets from vast amounts of GPS coordinate time series data.

关键词： GPS Coordinate time series Coseismic offset Signal detection

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Automatic Extraction Method of 3D Feature Guidelines for Complex Cultural Relic Surfaces Based on Point Cloud

引用

Journal of Geodesy and geoinformation Science 2024年第1期7卷 16-41页

作者： GENG Yuxin ZHONG Ruofei HUANG Yuqin SUN Haili College of Resources Environment and Tourism Capital Normal UniversityBeijing 100048China Key laboratory of 3-Dimensional Information Acquisition and Application Ministry of EducationBeijing 100048China Chinese Academy of Cultural Heritage Beijing 100029China

Cultural relics line graphic serves as a crucial form of traditional artifact information documentation,which is a simple and intuitive product with low cost of displaying compared with 3D *** reduction is undoubtedly necessary for line ***,most existing methods for artifact drawing rely on the principles of orthographic projection that always cannot avoid angle occlusion and data overlapping while the surface of cultural relics is ***,conformal mapping was introduced as a dimensionality reduction way to compensate for the limitation of orthographic *** on the given criteria for assessing surface complexity,this paper proposed a three-dimensional feature guideline extraction method for complex cultural relic surfaces.A 2D and 3D combined factor that measured the importance of points on describing surface features,vertex weight,was *** the selection threshold for feature guideline extraction was determined based on the differences between vertex weight and shape index *** feasibility and stability were verified through experiments conducted on real cultural relic surface *** demonstrated the ability of the method to address the challenges associated with the automatic generation of line drawings for complex *** extraction method and the obtained results will be useful for line graphic drawing,displaying and propaganda of cultural relics.

关键词： point cloud conformal parameterization vertex weight surface mesh cultural relics feature extraction

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Properties of L-band differential InSAR for monitoring mining-induced subsidence in coalfield of Jining, Northern China

引用

Journal of Central South University 2014年第4期21卷 1508-1517页

作者：陶秋香刘国林 Geomatics College Shandong University of Science and Technology Key laboratory of Surveying and Mapping Technology on Island and Reef of National Administration of Surveying Mapping and geoinformation

The properties and feasibility of L-band differential InSAR for detecting and monitoring mining-induced subsidence were systematically analyzed and demonstrated. The largest monitored subsidence gradient of 7.9×10-3 and magnitude of 91 cm were firstly derived by theoretical derivation. Then, the stronger phase maintaining capacity and weaker sensitivity to minor land subsidence compared with C-band DInSAR were illustrated by phase simulation of the actual mine subsidence. Finally, the data processing procedure of two-pass DInSAR was further refined to accurately observe subsidence of a coalfield of Jining in Northern China using 7 ALOS PALSAR images. The largest monitored subsidence magnitude of 39.22 cm and other properties were better investigated by testing results interpretation and subsidence analysis, and the absolute difference varying from 0.5 mm to 17.9 mm was obtained by comparison with leveling-measured subsidence. All of results show that L-band DInSAR technique can investigate the location, amount, area and other detailed subsidence information with relatively higher accuracy.

关键词：干涉合成孔径雷达沉降监测采动沉陷中国北方 L波段济宁差分煤田

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Trajectory-Oriented, Carriageway-Based Road Network data Model,Part 2:Methodology

引用

Geo-Spatial Information Science 2006年第2期9卷 112-117,150页

作者： LI Xiang LIN Hui Joint laboratory for geoinformation Science The Chinese University of Hong Kong Shatin N.T. Hong Kong

This is the second of a three-part series of papers which presents the principle and architecture of the CRNM, a trajectory-oriented, carriageway-based road network data model. The first part of the series has introduced a general background of building trajectory-oriented road network data models, including motivation, related works, and basic concepts. Based on it, this paper describs the CRNM in detail. At first, the notion of basic roadway entity is proposed and discussed. Secondly, carriageway is selected as the basic roadway entity after compared with other kinds of roadway, and approaches to representing other roadways with carriageways are introduced. At last, an overall architecture of the CRNM is proposed.

关键词：轨道网络数据模型地理信息系统道路系统

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Estimation of soil erosion risk within a small mountainous sub-watershed in Kerala,India,using Revised Universal Soil Loss Equation(RUSLE) and geo-information technology

引用

Geoscience Frontiers 2012年第2期3卷 209-215页

作者： V.Prasannakumar H.Vijith S.Abinod N.Geetha Centre for geoinformation Science and Technology University of Kerala

A comprehensive methodology that integrates Revised Universal Soil Loss Equation （RUSLE） model and Geographic Information System （GIS） techniques was adopted to determine the soil erosion vulner- ability of a forested mountainous sub-watershed in Kerala, India. The spatial pattern of annual soil erosion rate was obtained by integrating geo-environmental variables in a raster based GIS method. GIS data layers including, rainfall erosivity （R）, soil erodability （K）, slope length and steepness （LS）, cover management （C） and conservation practice （P） factors were computed to determine their effects on average annual soil loss in the area. The resultant map of annual soil erosion shows a maximum soil loss of 17.73 t h-1 y i with a close relation to grass land areas, degraded forests and deciduous forests on the steep side-slopes （with high LS ）. The spatial erosion maps generated with RUSLE method and GIS can serve as effective inputs in deriving strategies for land planning and management in the environmentally sensitive mountainous areas.

关键词： Soil erosion Revised Universal Soil Loss Equation (RUSLE)GIS Pamba Western Ghats Kerala

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Virtual representations of antique globes-new ways of touching the untouchable

引用

International Journal of Digital Earth 2008年第1期1卷 107-118,I0007页

作者： F.Hruby A.Riedl H.Tomberger Department of Geography and Regional research Cartography and GeoinformationUniversity of ViennaUniversita tsstrasse 71010 ViennaAustria

The starting point of this paper is the idea that a comprehensive understanding of the earth and its systems calls for consideration of bygone views of the *** facsimiles of antique globes in the form of digital globes provides a new opportunity to make such bygone world views accessible to a wide scientific ***,up to now,little practical experience in applying digital technology on globes has been *** these attempts by thorough synopsis,this article deduces a comprehensive approach on virtual representations of antique globes that can be described by the superordinate concept of virtual *** concept comprises facilities of data acquisition of the original globe,ways of visualising the digitised globe and its final cartographic *** that arise from this procedure are exemplified through both virtual hyperglobes and tactile *** findings on a 16th century earth globe are encouraging results of the presented virtual representation approach,which may offer a sustainable visualisation platform of interdisciplinary research.

关键词： 3D facsimile digital globe hyperglobe 3D visualisation digital restoration

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

An ERA5 tropospheric parameters-augmented approach for improving GNSS precise point positioning

引用

Geodesy and Geodynamics 2023年第5期14卷 467-476页

作者： Liangke Huang Feifan Liu Lijie Guo Guiwen Lan Lv Zhou Cheng Wang Lilong Liu College of Geomatics and geoinformation Guilin University of TechnologyGuilin 541006China Wuhan Changjiang Waterway Rescue and Salvage Bure Wuhan 430014China Guangxi Institute of Natural Resources Survey and Monitoring Nanning530023China

Precise Point Positioning(PPP) technology has developed into a potent instrument for geodetic positioning, ionospheric modeling, tropospheric atmospheric parameter detection, and seismic *** atmospheric reanalysis data products’ accuracy and spatiotemporal resolution have improved recently, it has become important to apply these products to obtain high-accuracy tropospheric delay parameters, like zenith tropospheric delay(ZTD) and tropospheric horizontal gradient. These tropospheric delay parameters can be applied to PPP to reduce the convergence time and to increase the accuracy in the vertical direction of the position. The European Centre for Medium-Range Weather Forecasts Reanalysis 5(ERA5) atmospheric reanalysis data is the latest product with a high spatiotemporal resolution released by the European Center for Medium-Range Weather Forecasts(ECMWF). Only a few researches have evaluated the application of ERA5 data to Global Navigation Satellite System(GNSS)PPP. Therefore, this study compared and validated the ZTD products derived from ERA5 data using ZTD values provided by 290 global International GNSS Service(IGS) stations for 2016-2017. The results indicated a stable performance for ZTD, with annual average bias and RMS values of 0.23 cm and 1.09 cm,respectively. Further, GNSS observations for one week in each of the four seasons(spring: DOY 92-98;summer: DOY 199-205;autumn: DOY 275-281;and winter: DOY 22-28) from 34 multi-GNSS experiments(MGEX) stations distributed globally in 2016 were considered to evaluate the performance of ERA5-derived tropospheric delay products in GNSS PPP. The performance of ERA5-enhanced PPP was compared with that of the two standard GNSS PPP schemes(without estimated tropospheric horizontal gradient and with estimated tropospheric horizontal gradient). The results demonstrated that ERA5-enhanced GNSS PPP showed no significant improvement in the convergence times in both the Eastern(E) and Northern(N) directions, while the

关键词： Precise point positioning ERA5 atmospheric reanalysis data Multi-GNSS Tropospheric delay

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Visualization of geologic geospatial datasets through X3D in the frame of WebGIS

引用

International Journal of Digital Earth 2013年第5期6卷 483-503页

作者： Frederik von Reumont Jamal Jokar Arsanjani Andreas Riedl Department of Geography and Regional research Cartography and GeoinformationUniversity of ViennaViennaAustria Geography and its Didactics University of Cologne50931CologneGermany

3D geo spatial data have become the ***,to view the data,usually expert software is required,which have up to now hindered the wide spread use of 3D scenes for the display of geological *** internet real time 3D rendering framework X3D is assessed regarding its suitability for building a geological GIS on the *** important for geological data,3D rendering enhances the intuitive grasp of the data and enables the user to interactively explore *** is often necessary to find a solution to distribute this data to a wide range of interested parties,experts and non-experts *** to the nature of 3D data,the best technique to display geo-data,the modeling of objects and unresolved issues have to be taken into *** internet is the apparent tool for the public distribution and visualization of 3D data and it was found that through the open ISO-standardized format X3D it offers a multitude of possibilities.A 3D geological interactive map was created with these prerequisites to identify challenges and possibilities through this *** was found that the use of lead to satisfactory results,that could probably not have been achieved with another technology.

关键词： webGIS geology X3D interactive map 3D visualization internet x3dom virtual reality

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：